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Biomedical subjects

C M Lee

Publications and source records attributed to C M Lee.

At least 109 records · Page 6Linked to original sources

Induced expression of neuronal membrane attack complex and cell death by Alzheimer's beta-amyloid peptide.

beta-amyloid peptide (A beta) and complement-derived membrane attack complex (MAC) are co-localized in senile plaques of brains from Alzheimer's disease (AD) patients. But the relationship between A beta and complement activation is unclear. We have used human neurotypic cells, differentiated SH-SY5Y, as a model system to examine regulation of neuronal MAC expression and cell death by A beta. We demonstrated that mRNAs (C1q, C2, C3, C4, C5, C6, C7, C8 and C9) and proteins (C1q, C3 and C9) for the major components of the classical complement cascade are present in the SH-SY5Y neurotypic cells, indicating that neuronal cells can synthesize the necessary proteins required for MAC formation. Furthermore, immunocytochemical studies showed the A beta-induced neuronal MAC expression on the SH-SY5Y cells after CD59 was removed by PIPLC or blocked by anti-CD59 antibody. Meanwhile, increased A beta-induced neuronal cell death was observed following treatment with anti-CD59. Taken together, these results suggest that A beta activates neuronal complement cascade to induce MAC, and a deficiency of endogenous complement regulatory proteins, e.g., CD59, may increase the vulnerability of neurons to complement-mediated cytotoxicity.

Alzheimer Disease↗

Dyslipidemias have a detrimental effect on left ventricular systolic function in patients with a first acute myocardial infarction.

Several large-scale clinical trials have shown that lipid-lowering interventions are associated with reduced coronary events and mortality. However, whether dyslipidemias have a detrimental effect on the evolution of myocardial infarction (MI) is still unknown. To examine whether dyslipidemias can aggravate myocardial vulnerability following MI, 165 patients with a first MI were studied. All patients underwent measurements of serum lipid profiles 1 week and 3 months after MI, a radionuclide ventriculographic study, and a coronary angiographic study. The patients were divided into 3 groups according to their 3-month serum cholesterol levels (group 1, <200 mg/dl; group 2, 200 to 240 mg/dl; group 3, >240 mg/dl). Groups 1, 2, and 3 consisted of 66, 59, and 40 patients, respectively. Group 3 had a higher Gensini score than groups 1 and 2, although this was not statistically significant (p = 0.13). The postinfarct left ventricular ejection fraction (LVEF) was highest in group 1 (53 +/- 13%), at mid level in group 2 (43 +/- 14%), and lowest in group 3 (35 +/- 11%) (p < 0.0001). A significant negative correlation between 3-month low-density lipoprotein (LDL) cholesterol (r = -0.55, p < 0.0001) and the postinfarct LVEF was found. The product of peak creatine kinase (CK(MAX)) and time to CK(MAX) (p = 0.001), and patency of the infarct-related artery (p = 0.009), rather than variables of coronary atherosclerosis, were also independent predictors of the postinfarct LVEF. Increases in 1-week LDL cholesterol and decreases in 1-week high-density lipoprotein cholesterol were associated with a higher CK(MAX) and a lower patency rate of the infarct-related artery, respectively. This study revealed that dyslipidemias per se, especially LDL cholesterol, had a detrimental effect on the postinfarct LVEF; this effect might be independent of the atherogenic properties of dyslipidemias.

Aged↗

A review of the kidneys that nobody wanted: determinants of optimal outcome.

BACKGROUND: We previously reported excellent outcome at 6 months after transplantation in recipients of expanded criteria donor kidneys that other local centers had declined, kidneys that nobody wanted (KNW), versus controls. We now report follow-up after 23 months. METHODS: We retrospectively reviewed 27 donor and 24 recipient characteristics in 126 adult recipients of transplants from January 1, 1995, to November 25, 1996. RESULTS: Donors of control kidneys versus KNW were younger and had significantly higher minimum 4-hr urine output. Recipients of control kidneys versus KNW had significantly more HLA matches and lower 3-month posttransplant serum creatinine levels. Patient and graft survival rates were similar between the control kidneys versus the KNW. We also compared the control kidneys and KNW with regard to prompt function or delayed graft function and satisfactory versus unsatisfactory function (unsatisfactory: serum creatinine > or =2.5 ml/dl or graft loss at 6 months) to identify donor and recipient characteristics associated with delayed graft function and unsatisfactory outcome. The incidence of rejection was significantly lower in control kidneys and KNW with satisfactory function versus control kidneys and KNW with unsatisfactory function. CONCLUSIONS: These data demonstrate: (1) similar graft survival at 12 months, (2) lower donor age, (3) higher minimum 4-hr urine output, and (4) more HLA matches in recipients of control kidneys versus KNW. Optimal outcome was achieved in recipients of control kidneys and KNW with prompt function and satisfactory function based upon serum creatinine in the first 6 months and in recipients with lower rates of rejection. Although outcome is dependent upon many donor and recipient variables, we believe that with careful donor and recipient selection, excellent outcome can be achieved using expanded criteria donor kidneys.

Actuarial Analysis↗

Outcome in cadaveric renal transplant recipients treated with cyclosporine A and mycophenolate mofetil versus cyclosporine A and azathioprine.

BACKGROUND: Recent multicenter reports have demonstrated improved outcome in recipients of cadaveric renal transplants treated with mycophenolate mofetil (MMF) versus azathioprine (AZA) in combination with cyclosporine A (CSA) and prednisone. We compared the outcome at our center in patients treated with MMF versus AZA, CSA, and prednisone. METHODS: We retrospectively reviewed 242 adult cadaveric renal transplant recipients treated between 11/91 and 5/97. We compared 25 donor variables and 27 recipient variables and outcome parameters between patients treated with MMF versus AZA. There were 117 patients treated with CSA+AZA, 84 with CSA+MMF, and 42 who received other immunosuppressive strategies. RESULTS: There were no significant differences in any clinically important donor variables. Patients treated with MMF versus AZA and CSA had significantly fewer rejections and readmissions. There was no significant difference in 1- or 2-year patient survival. Recipients treated with MMF had a 5% higher graft survival at 2 years, although the difference did not reach statistical significance. CONCLUSIONS: Outcome is improved in adult recipients of cadaveric renal transplants treated with MMF versus AZA in combination with CSA and prednisone.

Adult↗

Prognosis of dislocation after total hip arthroplasty.

One hundred sixty-one dislocations after cemented total hip arthroplasty, with a mean follow-up period of 8 years after dislocation, were reviewed with the aim of establishing the prognosis. There were 84% single and 16% recurrent dislocations. Closed reduction was successful in 81% of cases. Thirty-seven percent of dislocations were early (within 5 weeks), 36% occurred in patients who had had previous surgery, and in 47% there was nonunion of the trochanter. There was a two-way interaction between these factors, and all factors were significant for recurrent dislocation. Twenty-six (16%) recurrent dislocations required surgery. The most common causes of recurrent dislocation demonstrated at operation were component malposition (58%) and failure of the abductor mechanism (42%). In total, 96% of cases were successfully treated.

Adult↗

Children's adjustment to parental physical illness.

We review recent empirical literature examining the impact of parent physical illness on child functioning. We review studies of illness characteristics (n = 16), individual characteristics (n = 6), and family characteristics (n = 6). Although children's self-reports indicate heightened distress, parental reports do not suggest more problematic functioning. Child adjustment appears to be more closely related to perceptions of stressfulness rather than to objective illness severity indices. Adolescent girls seem to represent a group at heightened risk. Preliminary results suggest that family variables such as cohesion, conflict, and individual and family coping styles are important predictors of child adjustment.

Adaptation, Psychological↗

Determinative role of peroxidized low-density lipoprotein in myocardial thromboxane synthesis during pacing-induced ischaemia in humans.

1. Myocardial thromboxane A2 production increases in patients with pacing-induced ischaemia and correlates with a decrease in myocardial lactate extraction. The release of myocardial thromboxane A2 before any lactate production was observed in patients with unstable angina. This study was proposed to clarify whether the early thromboxane A2 release contributed to the ongoing myocardial ischaemia and to determine which metabolites can be attributed to the thromboxane A2 release. Thirty-five patients with chest pain and positive treadmill exercise test underwent atrial pacing to the predicted maximal heart rate. The pacing was maintained at this peak rate for 10 min, then ceased. Blood samples of the ascending aorta and coronary sinus were drawn simultaneously at rest, at 2 and 10 min of peak-pacing, and 5 and 10 min after termination of the pacing; samples were used for analyses of lipid profiles, prostacyclin, thromboxane A2, lactate and lipid peroxides on plasma and low-density lipoprotein particles. 2. Twenty out of 35 patients who displayed pacing-induced ischaemia were documented by electrocardiographic evidence of ST depression > 2 mm developing after 2 min of peak-pacing [ischaemic group, ST delta(+)]. They had (i) negative fractional lactate extraction; (ii) pacing-induced decreases of plasma thromboxane A2 levels in the coronary sinus blood (564 +/- 57 versus 479 +/- 47 ng/l, P < 0.05) at 2 min of peak-pacing; the data increased at 10 min of peak-pacing (564 +/- 57 versus 620 +/- 60 ng/l, P < 0.05), then returned to baseline levels at 5 and 10 min post-pacing; (iii) significantly increased lipid peroxides on low-density lipoprotein of the coronary sinus blood at 2 and 10 min of peak-pacing (each P < 0.001), as well as at 5 min post-pacing (P < 0.05); (iv) significant correlation between thromboxane A2 levels and lipid peroxides on low-density lipoprotein of the coronary sinus blood samples. 3. In ST delta(+) patients, myocardial thromboxane synthesis changed before lactate production and correlated with the increase of lipid peroxides on low-density lipoprotein of the coronary venous blood. This implies that lipid peroxides on low-density lipoprotein participate in thromboxane production and play a determinative role in pacing-induced ischaemia.

Analysis of Variance↗

All-trans beta-carotene is absorbed preferentially to 9-cis beta-carotene, but the latter accumulates in the tissues of domestic ferrets (Mustela putorius puro).

The algae Dunaliella bardawil and Dunaliella salina naturally contain large concentrations of all-trans and 9-cis beta-carotene (betaC). The purpose of this study was to compare the relative serum and tissue accumulation of all-trans and 9-cis betaC in ferrets fed different ratios of all-trans/9-cis betaC derived from two commercial sources, D. bardawil or D. salina (Betatene). Male ferrets (7 wk old) were fed carotene-free, pelleted diets for 27 d. Beginning on d 18, groups of ferrets (n = 6 or 7) received daily, one of six oral supplements varying in ratios of 9-cis and all-trans betaC mixed with approximately 1.0mL of Ensure. Four supplements containing 5.2-8.3 micromol total betaC were prepared from a 20% Betatene preparation, D. bardawil, a high-cis Betatene preparation, and Betatene further enriched in 9-cis betaC with all-trans betaC/9-cis betaC ratios of 2.2, 1.5, 0.6 and 0.4, respectively. Two control supplements, high and low betaC, were prepared from commercial betaC beadlets. The high control supplement had an all-trans/9-cis ratio of 19.0, whereas 9-cis betaC was not detected in the low supplement. On d 27, serum and tissues were obtained for HPLC analysis of betaC and its isomers. Analysis of livers showed that all-trans betaC was the primary isomer present, but 9-cis and other isomers were also detected in all groups. The hepatic all-trans/9-cis ratios were 5.9, 4.9, 2.5, 1.4, 52.2 and47.5, respectively, for the groups listed above. Lower amounts of all-trans and 9-cis betaC were found in kidneys compared with the liver, but ratios of all-trans/9-cis were not different among groups. Only trace amounts of 9-cis betaC were found in serum. These results demonstrate that the algae D. bardawil and D. salina provide a bioavailable source of betaC isomers, but, as in humans, absorption of 9-cis betaC is poor and any 9-cis betaC absorbed is apparently cleared by the liver.

Absorption↗

The mongolian gerbil (Meriones unguiculatus) is an appropriate animal model for evaluation of the conversion of beta-carotene to vitamin A.

Vitamin A (VA) deficiency is the leading cause of blindness in children in developing countries. Dietary intervention with foods rich in provitamin A carotenoids, such as beta-carotene (betaC), has been suggested as one solution to this problem. The objective of the two studies described in this paper was to examine the utilization of betaC as a source of VA at different stages of VA depletion using the Mongolian gerbil as a model. Male 4- to 5-wk-old Mongolian gerbils were fed powdered betaC-free semipurified diets either with or without VA for 26 d (Study 1), or without VA for 8-10 wk (Study 2). Gerbils were then fed diets with or without VA (20.9 nmol/g diet) and/or betaC [(67.0 micromol/g diet (Study 1) and 145.9 micromol/g diet (Study 2)] for variable periods. Two (Study 1) or three (Study 2) days before termination of the study, 3-4 gerbils per group were dosed orally with 14C-betaC. Tissues were evaluated for VA and betaC content by HPLC. Liver was extracted with and without saponification to evaluate 14C-betaC and 14C-VA content. The results demonstrate the following: 1) the gerbil is an appropriate animal model to study betaC utilization; 2) 20.9 nmol VA/g diet is more than sufficient for this species; 3) the daily VA utilization rate for this species is calculated to be 3.1 microg/100 g body weight; 4) a highly bioavailable source of betaC at a 6:1 weight ratio of betaC:VA is sufficient to reverse marginal VA status in this model; and 5) a highly bioavailable source of betaC fed between a 6:1 and 13:1 weight ratio to VA provides equivalent VA status as preformed VA in Mongolian gerbils.

Animals↗

Tissue stores of beta-carotene are not conserved for later use as a source of vitamin A during compromised vitamin A status in mongolian gerbils (Meriones unguiculatus).

Vitamin A (VA) deficiency remains a serious problem in the world today. Current approaches to preventing or treating VA deficiency, including dietary intervention with provitamin A compounds, rely on the body converting ingested beta-carotene (betaC) to VA. However, it is not known whether betaC that is already in the tissues can be used as a source of VA to prevent deficiency. The objectives of these studies were to determine whether tissue betaC stores are converted to VA when the Mongolian gerbils have low VA status and whether previously fed betaC is retained in the tissues for later conversion to VA. In the first study, gerbils were prefed diets with betaC (20.3 +/- 6.2 nmol/g diet) (+betaC) or without betaC (-betaC), and with VA [2.4 +/- 1.5 nmol/g diet (+betaC diet) or 12.0 +/- 4.2 nmol/g diet (-betaC diet)] for 7 d, and then depleted of both betaC and VA for up to 84 d. On d 0 after the prefeeding period, hepatic betaC stores were 13.3 +/- 9.1 nmol. These stores were significantly lower after 28d of consuming the -VA/-betaC diet (2.16 +/- 1.7 nmol), even though the hepatic VA concentrations did not change. In the second study, the gerbils were prefed a -VA/+betaC diet (74.3 +/- 19. 7 nmol betaC/g diet) for 7 d, and then fed a betaC-free diet either with (7.1 +/- 1.4 nmol/g) or without VA for up to 34 d. Hepatic betaC stores after the 7-d prefeeding period were 38.1 +/- 20.6 nmol, and were significantly higher than after 7d of consuming either a +VA/-betaC (12.4 +/- 10.8 mmol) or -VA/-betaC diet (11.4 +/- 8.0 nmol). The results from both studies suggest that a substantial amount of hepatic betaC is rapidly lost when betaC is eliminated from the diet and therefore is not conserved to meet later VA needs. The presence of VA in the diet (Study 2) did not affect the rate of betaC loss from the serum and tissues. Moreover, no evidence was found that the stored betaC was utilized for VA. The data suggest that there may be two pools of hepatic betaC, one that is lost rapidly and another that is lost more slowly over time, but losses are not affected by VA status.

Animals↗

Routine hospital admission for patients undergoing upper aerodigestive tract endoscopy is unwarranted.

Although upper aerodigestive tract endoscopy is commonly performed, the need for hospital admission remains controversial. A retrospective review of endoscopy performed between January 1, 1993, and June 30, 1995, identified 201 patients who underwent 371 procedures. Complications occurred in 34 of 371 (9.2%) procedures in 26 of 201 (12.9%) patients. Of these, 11 of 371 (3.0%) were major (requiring admission for management) and 23 of 371 (6.2%) were minor. For multiple concurrent procedures, the overall complication rate was 19.3% (22/114); 5.3% (6/114) were major and 14.0% (16/114) were minor. All 8 patients (100%) who went on to have major complications and 24 of the 26 (92.3%) who went on to have any complication were successfully identified prior to discharge; 2 required postdischarge outpatient management of urinary retention. Five statistically significant risk factors for complication were identified: preexisting cardiac conditions, American Society of Anesthesiologists rating, airway class rating, anesthesia type, and number of endoscopic procedures performed. A comparison of various approaches to hospital admission demonstrated that selective admission based on clinical judgment was superior to routine admission of all patients. In conclusion, we recommend that upper tract endoscopy be performed on an ambulatory basis because 1) the complication rate is low, 2) complications requiring inpatient management are identifiable in the immediate postoperative period, and 3) of the approaches to hospital admission examined, it was the most economical.

Adult↗

Pharmacological properties of ACh receptors on the heart of the marine bivalve Meretrix lusoria.

The cholinergic receptors on the heart of the marine bivalve Meretrix lusoria were used as a model to investigate their pharmacological properties in bivalves. By recording method, we measured the contractile force (CF) and the heart rate (HR) of the heart to examine the characteristics of cholinergic receptors of a marine bivalve. The known ACh receptor agonists or antagonists in vertebrate nervous system were then introduced into the heart by perfusion, to monitor their effects upon heart activities. Of the six tested agonists, two mAChR agonists (OXA-22, bethanechol) and two nAChR agonists (methylcarbachol, nicotine) mimicked the response induced by ACh. Among the seven tested antagonists, three mAChR antagonists (trihexyphenidy1, atropine and scopolamine) and three nAChR antagonists (TEA, curare and hexamethonium bromide) showed the antagonistic effects on the inhibition induced by ACh. However, there was one mAChR agonist, metoclopramide, that behaved like an ACh antagonist. Both APE (mAChR agonist) and PTMA (nAChR antagonist) showed no significant effects. This differences suggest that the pharmacological characteristics of ACh receptors on the heart of bivalve are different from those in vertebrates. It may be a novel type of ACh receptors.

Acetylcholine↗

Outcomes in diabetic patients after simultaneous pancreas-kidney versus kidney alone transplantation.

BACKGROUND: Previous studies have identified more morbidity in simultaneous pancreas-kidney (SPK) transplant recipients compared with kidney alone (KA) recipients. With the development of novel immunosuppressive drugs, studies are needed to determine optimal treatment regimens in specific patient populations. METHODS: We retrospectively compared short-term outcome in diabetic patients receiving either SPK or KA transplantation from December 10, 1991, to July 31, 1996. The SPK recipients received either cyclosporine (CsA) + azathioprine (AZA), FK506+AZA, or FK506 + mycophenolate mofetil (MM). KA group patients received either CsA+AZA or CsA+MM. RESULTS: Recipients of SPK instead of KA transplants were younger, had a longer mean length of stay, had a decreased incidence of delayed graft function, and had more readmissions. There were no significant differences in serum creatinine at 1, 2, and 3 years after transplantation, number of rejection episodes and infections, incidence of kidney graft loss and patient death, and 1- and 3-year actuarial patient and kidney graft survival rates between the two groups. Diabetic SPK patients receiving FK506+MM had a higher mean 3-month creatinine clearance (calculated), compared with recipients of CsA+AZA or FK506+AZA. Diabetic patients after KA transplantation who received CsA+MM demonstrated fewer rejection episodes and graft losses, although differences did not reach statistical significance. CONCLUSIONS: (1) Diabetic SPK recipients have decreased rates of delayed graft function and more readmissions compared with diabetic KA recipients. (2) There is no difference in: serum creatinine levels up to 3 years after transplantation, number of rejection episodes or infections, and 1- and 3-year patient and graft survival rates between SPK and KA recipients. (3) Short-term outcome is improved in diabetic recipients of SPK and KA transplants receiving MM instead of AZA.

Adolescent↗

When should expanded criteria donor kidneys be used for single versus dual kidney transplants?

BACKGROUND: To increase the utilization of cadaveric donor kidneys, we have recently expanded our acceptable criteria to include aged donors (frequently with a history of hypertension), by selectively using both donor kidneys (dual transplant) into a single recipient. METHODS: To define when these expanded criteria donor (ECD) kidneys should be used as a single versus a dual kidney transplant, we retrospectively reviewed 52 recipients of ECD kidneys that had been turned down by all other local centers between 1/1/95 and 11/15/96. Fifteen patients received dual transplants, whereas the remaining 37 received single kidneys. Of the dual kidney recipients, 14 of 15 ECD were > or = 59 years of age, 10 of 15 were hypertensive, and 9 of 15 were both. Of the single recipients, 11 of 37 ECD were > or = 59 years of age, 11 of 37 were hypertensive, and 7 of 37 were both. All patients received cyclosporine-based triple-drug therapy. We compared seven donor (D) and sixteen recipient outcome variables in single versus dual kidney transplants as subgrouped by: (1) donor admission creatinine clearance (D-AdC(Cr)) < 90 ml/min; (2) D-age > or = 59 years; and (3) cold storage (Cld Stg) < or > 24 hr. RESULTS: In the group with D-AdC(Cr) < 90, there was a significantly higher incidence of delayed graft function (DGF) in single versus dual recipients (9 of 20 [45%] vs. 1 of 11 [9%]; P=0.04) and worse early graft function based upon mean serum creatinine at 1 and 4 weeks (5.3+/-3.3 and 2.8+/-2.0 vs. 1.7+/-0.6 and 1.4+/-0.5 mg] dl; P<0.05). In the group with D-age > or = 59, recipients of single kidneys had significantly higher mean serum creatinine at 1, 4, and 12 weeks versus recipients of dual kidneys (5.1+/-3.3, 3.4+/-2.1, 2.8+/-1.5 versus 2.8+/-2.5, 1.5+/-0.6, 1.6+/-0.5 mg/dl; P<0.05). Cld Stg time also had an impact on DGF and early outcome. Recipients of dual kidneys stored less than 24 hr had a significantly lower incidence of DGF versus single kidneys stored more than 24 hr (10% vs. 46%; P<0.05) and better early graft function based on mean serum creatinine at 1, 4, and 12 weeks (1.9+/-0.8, 1.3+/-0.4, 1.5+/-0.2 vs. 6.6+/-3.4, 3.0+/-1.6, 2.9+/-1.9 mg/dl; P<0.05). The overall 1-year patient and graft survivals were 96% and 81% vs. 93% and 87% (P=NS) in recipients of single ECD versus dual ECD kidneys. CONCLUSIONS: In conclusion, we believe that kidneys from ECD with D-AdC(Cr) < 90 ml/min and D-age > or = 59 should be used as dual kidney transplants, keeping the Cld Stg time at < 24 hr to minimize the effect of Cld Stg on early graft function.

Adult↗

A substitute for facial replica in mannequin procedures.

The use of mannequin exercises has been a teaching tool in the education of dental students. Various commercially available materials to simulate extraoral facial structure form part of this apparatus, also called a "phantom head." It is not always practical, with cost considerations, to replace this external component when unavoidable wear and tear occurs. An alternative that uses a recycled milk carton is presented as an inexpensive substitute.

Dental Prosthesis Design↗

CT angiography of intracranial aneurysms: advantages and pitfalls.

OBJECTIVE: To determine the clinical usefulness of computed tomography (CT) angiography in the evaluation of cerebral aneurysms. MATERIALS AND METHODS: From October 1994 through April 1996, 26 patients with 30 surgical proven intracranial aneurysms underwent both CT angiography and catheter cerebral angiography. The findings of the two methods were reviewed independently and then compared with each other. RESULTS: Comparing with catheter angiography, CT angiography was superior in demonstrating the aneurysmal neck in seven aneurysms but was inferior in one. The thrombosed part and calcification of aneurysms were clearly demonstrated on CT angiograms. CT angiography also aided in differentiating tight vascular loops from aneurysms. On CT angiograms, one posterior communicating arterial aneurysm was overlooked and another anterior choroidal artery aneurysm was misinterpreted as a posterior communicating artery aneurysm. Of note were two patients in whom the infundibulum of the orbitofrontal artery was misinterpreted as the anterior communicating artery aneurysm. CONCLUSION: CT angiography can compliment conventional catheter angiography for its better demonstration of the 3-dimensional anatomy. It can provide surgical information about the neck, calcification and thrombosed part of an aneurysm and its relation to adjacent structures. However, caution is advocated because CT angiography may fail to demonstrate small but important vessels such as posterior communicating, anterior choroidal and orbitofrontal arteries. Recognition of the limitations of CT angiography is important in minimizing interpretation errors.

Adult↗

Age-associated alterations of the mitochondrial genome.

Age-associated alterations of the mitochondrial genome occur in several different species; however, their physiological relevance remains unclear. The age-associated changes of mitochondrial DNA (mtDNA) include nucleotide point mutations and modifications, as well as deletions. In this review, we summarize the current literature on age-associated mtDNA mutations and deletions and comment on their abundance. A clear need exists for a more thorough evaluation of the total damage to the mitochondrial genome that accumulates in aged tissues.

Aging↗