Long-term survival of an infant with diffuse brainstem lesion diagnosed by prenatal MRI: a case report and review of the literature.

BACKGROUND: We describe a unique case of expansive diffuse brainstem lesion diagnosed prenatally by magnetic resonance imaging (MRI) with long-term survival. Findings of fetal and postpartum MRI were highly consistent with the characteristics of diffuse brainstem glioma. METHODS: Diagnosis was based on the features of MRI, and histopathology was not confirmed by biopsy. Although the prognosis of diffuse brainstem tumor is usually poor, this child was asymptomatic at birth and the neurological condition is still normal at 4 years of age without any treatment. RESULTS: During routine imaging follow-up, diameters of the expansion have remained stable, while the size of the lesion compared to the posterior fossa size has diminished. In addition to brainstem tumor, a skin lesion of the back was observed and MRI of the thoracic spine showed a large asymptomatic extradural cystic lesion suggesting an arachnoid cyst. The pontine tumor of this infant, in agreement with a few previously reported cases, suggests a subgroup of beneficial outcome of expansive diffuse brainstem lesions, particularly in the neonatal period. DISCUSSION: In this article, we discuss the prognosis and characteristics of pediatric brainstem tumors and differential diagnosis of neonatal brainstem lesions.

Physical health of singleton children born after frozen embryo transfer using slow freezing: a 3-year follow-up study.

STUDY QUESTION: Are there differences in the physical health of singleton children born after frozen embryo transfer (FET) compared with children born after fresh embryo transfer (fresh ET)? SUMMARY ANSWER: Register-based health indicators were similar among FET and fresh ET singletons during a 3-year follow-up. WHAT IS KNOWN ALREADY: Large cohort studies have shown that perinatal outcomes are similar or even better in FET than fresh ET children. The early childhood morbidity among FET and fresh ET children has been shown to be quite similar, but so far these studies have been small. The short-term health outcomes of assisted reproductive technology (ART) children have been shown to be slightly worse compared with spontaneously conceived children. STUDY DESIGN, SIZE, DURATION: This register-based study includes women who had undergone ART treatments leading to singleton live births (n = 4758 children) in 1995-2006. A 10% random sample of women with spontaneous pregnancies from the Finnish Medical Birth Register (FMBR) served as the reference group (n = 31 137 children). The children were identified through the FMBR by using the mother's personal identification (ID) number. Children's ID numbers were linked with two nationwide registries; the Finnish Hospital Discharge Register and the Cause-of-Death Register at Statistics Finland. Information on all visits was received until 2009 using ICD-10 codes. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study includes 1825 children born after FET, 2933 children born after fresh ET and 31 137 children born after spontaneous pregnancies. The risk estimates for diseases were adjusted for the child's year of birth and maternal age, parity, socio-economic status and prematurity. The study focused on the differences between FET and fresh ET children. MAIN RESULTS AND THE ROLE OF CHANCE: Most health indicators were similar among FET and fresh ET children during the 3-year follow-up. The most common discharge diagnoses, including gastroenteritis and colitis, otitis, upper and lower respiratory diseases, asthma and allergies were similar between the ART groups. A large proportion of FET children (70.1%) and fresh ET children (69.9%) had visited a hospital at least once (P = 0.877). The risk of hospital admission did not differ between the two groups after adjusting for premature births [adjusted odds ratio (aOR) 1.01; 0.88-1.17]. Comparing with children born after spontaneously conceived pregnancies, the risk of hospital admission was slightly increased in the ART group, even after adjusting for premature births (aOR 1.10; 1.02-1.19). LIMITATIONS, REASONS FOR CAUTION: Due to the study design, we were not able to control for some parental background factors, such as the cause and length of infertility. Furthermore, the health registries do not include data on the growth of the children. Our findings are generalizable only to the slow-freezing method. WIDER IMPLICATIONS OF THE FINDINGS: Our study provides further evidence of the safety of embryo cryopreservation. The early physical health of FET children is similar to that of children born after fresh ET. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the University Hospital of Oulu and Helsinki, Finland. The National Institute for Health and Welfare (THL) covered the data linkages and the work of Mika Gissler. There are no competing interests to be reported.

Routine exercise alters measures of immunity and the acute phase reaction.

PURPOSE: To expand our understanding of the overall anti-inflammatory nature of routine exercise; we compared resting blood values from adults who habitually undertake frequent, moderate levels of exercise to reference interval values assumed to reflect values largely from non-exercisers. This information would be useful for clinicians interpreting blood tests assessing inflammatory, immune and acute phase responses. METHODS: Blood samples were collected from 119 community adult self-reported routine exercisers (61 males and 58 females aged 18-60 years). Samples were analysed for 20 cellular and non-cellular biomarkers which included 11 immunological and 9 acute phase reactants. These data were compared to reference intervals from the same hospital laboratory that performed the analyses on our participants' samples. Individual analyte values were also compared with participants' self-reported 150 day exercise patterns which included exercise frequency, intensity and duration. RESULTS: In general, mean values for routine exercise participants fell at the lower end of laboratory reference interval for most inflammatory analytes. More than 10 % of participants had numbers of CD19(+), CD8(+) and 16/56(+) NK cells below the low end of the respective reference interval. More than 10 % of observed acute phase reactant values (for C3, haptoglobin and ferritin) were also below the low end of the reference interval. At rest IgM (r = -0.22) and IgG (r = -0.31) values correlated negatively (p < 0.05) with exercise load. CONCLUSIONS: Routine exercise appears to lower resting numbers of a variety of immune cell-types as well as the concentration of several classical acute phase reactants. These wide-ranging systemic effects are presumably adaptive changes, not pathology and collectively confirm the well-reported and clinically important anti-inflammatory effects of exercise.

A tRNA suppressor mutation in human mitochondria.

Mitochondrial mutations are associated with a wide spectrum of human diseases. A common class of point mutations affects tRNA genes, and mutations in the tRNA-leu(UUR) gene (MTTL1) are the most frequently detected. In earlier studies, we showed that lung carcinoma cybrid cells containing high levels (greater than 95%) of mutated mtDNA from a patient with the pathological nucleotide pair (np) 3243 tRNA-leu(UUR) mutation can remain genotypically stable over time, and exhibit severe defects in mitochondrial respiratory metabolism. From such a cybrid containing 99% mutated mtDNA, we have isolated a spontaneous derivative that retains mutant mtDNA at this level but which has nevertheless reverted to the wild-type phenotype, based on studies of respiration, growth in selective media, mitochondrial protein synthesis and biogenesis of mitochondrial membrane complexes. The cells are heteroplasmic for a novel anticodon mutation in tRNA-leu(CUN) at np 12300, predicted to generate a suppressor tRNA capable of decoding UUR leucine codons. The suppressor mutation represents approximately 10% of the total mtDNA, but was undetectable in a muscle biopsy sample taken from the original patient or in the parental cybrid. These results indicate that the primary biochemical defect in cells with high levels of np 3243 mutated mtDNA is the inability to translate UUR leucine codons.

Genotypic stability, segregation and selection in heteroplasmic human cell lines containing np 3243 mutant mtDNA.

The mitochondrial genotype of heteroplasmic human cell lines containing the pathological np 3243 mtDNA mutation, plus or minus its suppressor at np 12300, has been followed over long periods in culture. Cell lines containing various different proportions of mutant mtDNA remained generally at a consistent, average heteroplasmy value over at least 30 wk of culture in nonselective media and exhibited minimal mitotic segregation, with a segregation number comparable with mtDNA copy number (>/=1000). Growth in selective medium of cells at 99% np 3243 mutant mtDNA did, however, allow the isolation of clones with lower levels of the mutation, against a background of massive cell death. As a rare event, cell lines exhibited a sudden and dramatic diversification of heteroplasmy levels, accompanied by a shift in the average heteroplasmy level over a short period (<8 wk), indicating selection. One such episode was associated with a gain of chromosome 9. Analysis of respiratory phenotype and mitochondrial genotype of cell clones from such cultures revealed that stable heteroplasmy values were generally reestablished within a few weeks, in a reproducible but clone-specific fashion. This occurred independently of any straightforward phenotypic selection at the individual cell-clone level. Our findings are consistent with several alternate views of mtDNA organization in mammalian cells. One model that is supported by our data is that mtDNA is found in nucleoids containing many copies of the genome, which can themselves be heteroplasmic, and which are faithfully replicated. We interpret diversification and shifts of heteroplasmy level as resulting from a reorganization of such nucleoids, under nuclear genetic control. Abrupt remodeling of nucleoids in vivo would have major implications for understanding the developmental consequences of heteroplasmy, including mitochondrial disease phenotype and progression.

Longitudinal neuropsychological and genetic linkage analysis of persons at risk for Huntington's disease.

OBJECTIVE: To determine (1) whether the neuropsychological profiles of healthy individuals at risk (AR) for Huntington's disease who were positive (AR/+) or negative (AR/-) for the Huntington's disease genetic marker differed from those of symptomatic patients with Huntington's disease and normal control individuals and (2) whether the neuropsychological performance of the two AR groups differed from each other on three assessments during a 4-year span. DESIGN: Case-control, double-blind study, with AR status determined by genetic linkage analysis (G8 probe), in addition to examination of trinucleotide repeats for most AR subjects. SETTING: The Neuropsychology Program in the Department of Psychiatry and the Department of Neurology at the University of Michigan Medical Center, Ann Arbor, a tertiary care center. PARTICIPANTS: Eight subjects matched as closely as possible for age, gender, and education in each of the following groups: AR/+, AR/-, normal control, and Huntington's disease. MEASURES: A battery of neuropsychological tasks, including measures of intelligence, memory, problem solving, and motor ability. RESULTS: Although both AR groups demonstrated variability on select intellectual subtests relative to normal subjects, they did not differ from each other on the three assessments during a 4-year span. Patients with Huntington's disease performed more poorly than the other groups across a range of neuropsychological measures. CONCLUSIONS: These results do not support previous evaluations concluding that AR/+ individuals demonstrate cognitive impairments as compared with AR/- individuals. Findings in earlier studies without genetic linkage analysis of lower performance of AR individuals, including children, as compared with normal controls may relate to extraneous environmental and familial issues that interfere with intellectual development.

Neuropsychological changes in olivopontocerebellar atrophy.

We used standardized neuropsychological measures of intellectual, cognitive, psychomotor, and emotional functioning to compare 39 patients with olivopontocerebellar atrophy and 25 normal controls of similar age. The patients reflected greater depression, anxiety, and subjective emotional discomfort than did the control subjects. While 4 of the patients had below-normal IQ scores (Wechsler Adult Intelligence Scale [WAIS-R] Full-Scale IQ [FSIQ] less than 80), their clinical histories suggested lifelong functioning at such levels. As a group, the patients were not abnormal in general intellectual functioning and related cognitive abilities (WAIS-R FSIQ, mean [+/- SD], 93.46 +/- 13.19; Wechsler Memory Scale mental quotient, 108.95 +/- 17.43). These scores were lower than those of the normal controls (WAIS-R FSIQ, 113.72 +/- 12.68; mental quotient, 127.80 +/- 12.40); however, the controls were a highly educated group with intelligence levels that were higher than those of the average population. Moreover, when education and motor dysfunction were statistically covaried, no significant differences between the patients and the normal controls were apparent on the cognitive and intellectual tasks. Further analysis of specific memory performance in a subgroup of patients and controls matched for age, sex, and education yielded findings that were comparable with the overall group analysis. We conclude that motor dysfunction and depressed mood could leave patients with olivopontocerebellar atrophy appearing to be impaired in memory, even demented, when they are not.

The utility and generality of Mini-Mental State Examination scores in Alzheimer's disease.

The present study sought to evaluate the validity and generality of the Mini-Mental State Examination (MMSE) and its subsection scores. We gave the MMSE and other neuropsychological tests to 51 patients with probable Alzheimer's disease. On the basis of correlational and factor analyses, overall performance on the MMSE proved to have good concurrent validity with other comprehensive neuropsychological assessment instruments. However, the MMSE subsections should not be viewed as highly specific measures of cognition or memory.

Apolipoprotein E polymorphism, serum lipids, myocardial infarction and severity of angiographically verified coronary artery disease in men and women.

In several populations, the apolipoprotein E (apo E) allele epsilon 4 is associated with high concentration of plasma total and low density lipoprotein (LDL)-cholesterol and coronary artery disease (CAD). We determined the apo E phenotypes of 309 patients with angiographically verified CAD and 38 patients without CAD by isoelectric focusing and Western blotting. In men with CAD, the plasma total and LDL-cholesterol increased according to apo E phenotype in the following order: E3/2 < E3/3 < E4/3 < E4/4 (P = 0.03 for total cholesterol, P = 0.007 for LDL-cholesterol). In women, there was a similar trend (P = 0.22 for total cholesterol, P = 0.15 for LDL-cholesterol). The relative frequency of men with three vessel CAD increased (P = 0.43) together with LDL-cholesterol levels (P = 0.05) according to apo E phenotype E3/2, E3/3, E4/3, E4/4. Total and LDL-cholesterol levels were higher in patients with three vessel CAD than in patients with less serious types of CAD (P = 0.02 for total cholesterol, P = 0.007 for LDL-cholesterol). The relative frequency of patients with myocardial infarction increased according to apo E phenotype (P = 0.51). Both in men and women, there were no differences between apo E phenotypes in age at occurrence of the first myocardial infarction. The apo E allele frequencies of patients with CAD vs. without CAD were 2.3% vs. 1.3% for epsilon 2, 79.0% vs. 76.3% for epsilon 3 and 18.7% vs. 22.4% for epsilon 4. There were no statistically significant differences in apo E allele or phenotype frequencies between patients with CAD and without CAD or between patients with CAD and the general Finnish population. Our results support previous studies in suggesting that the apo E allele epsilon 4 is a risk factor for atherosclerosis, which affects plasma total and LDL-cholesterol. In addition, our results suggest that the apo E allele determines the severity of CAD.

Scanning electron microscopy and X-ray microprobe analysis in detection of acetylcholinesterase in cultured embryonal carcinoma cells.

Mouse F9 cells, induced by retinoic acid and dibutyryl cyclic adenosine monophosphate (cAMP) to differentiate into neural-type cells, were incubated for localization of specific acetylcholinesterase (AChE) activity according to the Karnovsky-Roots method where the final enzymatic reaction product is crystalline cupric ferrocyanide and cuprous thiocholine iodide. By scanning electron microscopy (SEM) neural-type cells with long processes were seen. Most of these cells exhibited crystalline precipitates on their surface that in microprobe analysis contained copper, iron, and sulfur. These elements were also detected in some of the neural-type cells that had no visible surface precipitates. Thus, the X-ray analysis also revealed intracellular enzymatic activity. Undifferentiated rounded cells, devoid of AChE activity at the light microscope level, did not show any surface precipitates by SEM and lacked copper, iron, and sulfur emission peaks in the elementary analysis. These results demonstrate that elementary analysis of cytochemical enzymatic reaction products by SEM can be used in identifying cells.

Rod-like intramitochondrial inclusions after hypothermic chemical cardioplegia during cardiac operations.

Rod-like intramitochondrial inclusions in the myocardial cells were observed after hypothermic chemical cardioplegia in three out of 20 patients who underwent coronary bypass operations. They were not seen in another group of 20 patients who underwent an aortic valve replacement operation in whom only topical cooling was used for myocardial protection. The occurrence of rod-like intramitochondrial inclusions could not be correlated with other signs of ischemic myocardial injury. X-ray microanalysis did not reveal any inorganic substance in the intramitochondrial inclusions. Therefore, we believe that their occurrence was not related to the calcium paradox phenomenon, a feared complication of cardiac operations.

Verbal fluency and positron emission tomographic mapping of regional cerebral glucose metabolism.

Impairment in verbal fluency (VF) has been a consistently reported clinical feature of focal cerebral deficits in frontal and temporal regions. More recent behavioral activation studies with healthy control subjects using positron emission tomography (PET), however, have noted a negative correlation between performance on verbal fluency tasks and regional cortical activity. To see if this negative relationship extends to steady-state non-activation PET measures, thirty-three healthy adults were given a VF task within a day of their 18F-2-fluoro-2-deoxy-D-glucose PET scan. VF was found to correlate positively with left temporal cortical region metabolic activity but to correlate negatively with right and left frontal activity. VF was not correlated significantly with right temporal cortical metabolic activity. Some previous studies with normals using behavioral activation paradigms and PET have reported negative correlations between metabolic activity and cognitive performance similar to that reported here. An explanation for the disparate relationships that were observed between frontal and temporal brain areas and VF might be found in the mediation of different task demands by these separate locations, i.e., task planning and/or initiation by frontal regions and verbal memory by the left temporal area.

Micellar electrokinetic capillary chromatography method for direct determination of glucuronides of entacapone and its (Z)-isomer in human urine.

This paper describes the validation of a micellar electrokinetic capillary chromatography method for the direct determination of the 3-O-glucuronides of entacapone and its (Z)-isomer, the main urinary metabolites of entacapone in humans. Entacapone is a novel drug which, as a potent inhibitor of catechol-O-methyltransferase (COMT), is used as an adjunct in the standard therapy of Parkinson's disease. The 3-O-glucuronide of another COMT inhibitor, nitecapone, was used as internal standard (I.S.). The validation experiments were performed by using spiked urine samples that were extracted with Sep-Pak C18 cartridges before analysis. Determinations were carried out in a buffer of pH 7.0 containing 25 mM of phosphate, 50 mM of borate and 20 mM of sodium dodecyl sulfate, and by applying 15 kV over a 67 cm (60 cm to the detector) x 75 microns fused-silica capillary. UV detection was at 335 nm. The validity of the method was assessed by investigating the identity of the analytes, selectivity, limit of quantitation, linearity, within-day precision, extraction recovery, between-day precision and accuracy, electroosmotic flow stability and analyte stability. The method proved to be reproducible, sufficiently selective and accurate. Extraction recoveries of the analytes were > 94%. The limit of quantitation (LOQ) was 2 micrograms/ml and the assay was linear in the range 2-150 micrograms/ml with correlation coefficients better than 0.999 for both glucuronides. The repeatability of the method, expressed as the ratio of corrected peak area of the analytes to that of I.S., gave RSD values of < 5% even at the LOQ. Between-day precision (RSD) was < 7.5% for both glucuronides at 7.5 micrograms/ml. Determination of the glucuronide concentrations in urine samples of 34 patients treated with entacapone either orally (200 mg) or intravenously (25 mg) showed the method to be suitable for monitoring the concentrations of the glucuronide of entacapone after both oral and intravenous administration and those of the glucuronide of its (Z)-isomer after oral administration. The limited long term stability of the system requires, however, frequent recalibration in applications involving long sample series.

Isolation and characterization of hot particles from Chernobyl fallout in southwestern Finland.

Three types of activity composition have been found in airborne hot particles that were transported long distances from the Chernobyl accident. Their characterization is based on the analysis of single particles isolated from Pinus Sylvestris needles. The average activity of the particles was 130 Bq at the time of the accident. The most common type of particle contains the radioactive species 141Ce, 144Ce, 95Zr and 95Nb; the second type includes 103Ru and 106Ru along with the previous isotopes; and the third contains 103Ru and 106Ru only. Cesium-134 and -137 were present only in very small amounts. The activity composition of the Chernobyl reactor core fuel was similar to the composition of the first and second type particle; apparently the core fuel was only partially volatilized. The main bulk composition of the particles is shown to be U. The average aerodynamic size of the identified hot particles is 10 microns. The particles are rectangular or pentagonal in shape.

Serum lipid levels and M/L55 allele distribution of HDL paraoxonase gene in Saami and Finnish men.

Paraoxonase (PON) is an antioxidative enzyme, which eliminates lipid peroxides. The mutation in codon 55 of PON1 gene causes a change of methionine (M-allele) to leucine (L-allele) and influences PON activity. The Saami are a population living in the northern part of Fennoscandia. In previous studies their death rate from coronary artery disease (CAD) was found to be low. We compared PON M/L55 allele frequencies of 68 Saami and 68 Finnish men and related the PON genotypes to plasma lipid levels and to the levels of autoantibodies against oxidized LDL. The M/L55 genotypes were determined by PCR and restriction enzyme digestion. ELISA was used to measure antibodies against oxidized LDL. The L- and M-allele frequencies were 64% and 36% in Saami population and 64% and 36% in Finnish men, respectively (p = NS, Fisher's exact test). There were also no significant differences in plasma lipid levels or in antibody levels against oxidized LDL between PON genotypes or between Saami and Finnish men. Our results indicate that the PON M/L55 genotype is not associated with plasma lipid levels or the levels of autoantibodies against oxidized LDL in these populations. The Saami men have the same PON M/L55 allele distribution as the Finnish men and the PON genotype might thus not be one factor protecting Saami against CAD.

Apolipoprotein E and A-IV polymorphisms in ethnic Russians living in Estonia.

137 Russians living in Estonia was screened by isoelectric focusing and immunoblotting procedures to determine the distribution of genetic variations in apolipoprotein E (apoE) and apolipoprotein A-IV (apoA-IV) genes. The apoA-IV-2 allele and epsilon4 allele frequency of the Russians tended to be lower than in most other European populations.

Cost-effectiveness of intensive adjuvant chemotherapy for high-risk breast cancer: is tailored and dose-escalated chemotherapy with growth factor support (GFS) more costly and less effective than marrow-supported high-dose chemotherapy - results from a randomized study.

Based on randomized studies bone-marrow supported (BMS) high-dose chemotherapy (HDCT) is not superior to conventional CT as adjuvant treatment for high-risk breast cancer. To compare the cost-effectiveness of these treatments we examined the data of Finnish patients in the SBG9401 trial 1. Patients were randomized to receive either dose-escalated (de FEC) (group A, n =59) or FEC and HDCT+BMS (group B, n =70). They received adjuvant radiotherapy (RT) + tamoxifen. All direct health care costs of first line treatment at the oncology units were considered as well as productivity costs within the first 3 years of follow-up. Effectiveness was measured by the number of survival days during 5 years of follow-up. The mean direct health care costs were significantly higher in group B (25829 euro in group A vs. 36605 euro in group B, p <0.001), mainly due to a higher number of hospital days. Half of the costs in group A was due to the use of filgrastim (15335 euro in A and 2969 euro in B, p <0.001). The costs of RT were only 5% of total costs. There was no statistically significant difference between the groups in the number of survival days, but sensitivity analysis based on bootstrapping suggested that treatment A would be a less costly and more effective alternative in a great majority of cases.

Down-regulation of nuclear binding activities of OXBOX-REBOX transcription factors during cellular senescence.

Functional capacity of mitochondria declines during aging and this impairment may have a major role in aging process. Several observations indicate that transcriptional efficiency is reduced during aging. Our purpose was to find out whether aging and cellular senescence affect the nuclear binding activities of transcription factors which bind to OXBOX-REBOX sequence present in promoter regions of numerous nuclear genes encoding mitochondrial proteins. These factors regulate and coordinate the expression of mitochondrial proteins. We observed a strong down-regulation in the nuclear binding activities of OXBOX-REBOX factors in replicatively senesced human WI-38 and IMR-90 fibroblasts. On the contrary, SV-40 immortalization highly increased the nuclear binding activities. A considerable down-regulation of OXBOX-REBOX factors was also observed in UVB-irradiated WI-38 fibroblasts. Irradiation induced photoaging in fibroblasts which involved cell cycle arrest and senescent morphology. Interestingly, the nuclear binding activities of OXBOX-REBOX factors were also prominently decreased in the liver of Wistar rats at the age of 30 months but not yet at the age of 18 months. Our results suggest that the down-regulation of OXBOX-REBOX factors could affect the expression level of mitochondrial proteins encoded in nucleus and hence induce disturbances in mitochondrial function and promote the cellular aging process.

Changes associated with aging and replicative senescence in the regulation of transcription factor nuclear factor-kappa B.

Both the aging of animals and the senescence of cultured cells involve an altered pattern of gene expression, suggesting changes in transcription factor regulation. We studied age-related changes in transcription factors nuclear factor (NF)-kappa B, activator protein factor-1 (AP-1) and Sp-1 by using electrophoretic mobility shift binding assays; we also analysed changes in the protein components of NF-kappa B complex with Western blot assays. Nuclear and cytoplasmic extracts were prepared from heart, liver, kidney and brain of young adult and old NMRI mice and Wistar rats as well as from presenescent, senescent and simian virus 40-immortalized human WI-38 fibroblasts. Aging of both mice and rats induced a strong and consistent increase in the nuclear binding activity of NF-kappa B factor in all tissues studied, whereas those of AP-1 and Sp-1 decreased, e.g. in liver. Protein levels of p50, p52 and p65 components of the NF-kappa B complex did not show any age-associated changes in the cytoplasmic fraction but in the nuclear fraction the level of p52 strongly increased in heart and liver during aging. The protein levels of inhibitory I kappa B-alpha and Bcl-3 components were not affected by aging in any of the tissues studied. Replicative cellular senescence of human WI-38 fibroblasts induced a strong decrease in nuclear NF-kappa B, AP-1 and Sp-1 binding activities. Protein levels of p50 and p52 components of NF-kappa B complex were decreased in the nuclear fraction of senescent WI-38 fibroblasts but in the cytoplasm of senescent fibroblasts the level of p65 protein was increased. Cellular senescence also slightly decreased the protein levels of I kappa B-alpha and Bcl-3. Transfection assays with NF-kappa B-enhancer-driven chloramphenicol acetyltransferase reporter gene showed a significant down-regulation of NF-kappa B promoter activity in senescent WI-38 fibroblasts. Results suggest that the aging process might be regulated differently in tissues and cultured fibroblasts, perhaps reflecting differences between mitotic and post-mitotic cells. In tissues, aging seems to involve specific changes in the regulation of NF-kappa B components and perhaps also changes in the DNA-binding affinities of the NF-kappa B complex.

Heteroplasmic segregation associated with trisomy-9 in cultured human cells.

In cybrid cells carrying the mitochondrial A3243G MELAS mutation, which were also heteroplasmic for the G12300A suppressor mutation, we observed a transient episode of heteroplasmic instability, resulting in a wide diversification in G12300A heteroplasmy levels and a shift in the average heteroplasmy level from 11 to 29%. These cells were found to be trisomic for chromosome 9, whereas a minority of cells that retained disomy-9 showed no instability. Coculture experiments implied that trisomy-9 cells exhibited a significant growth advantage, but neither heteroplasmy levels, respiratory phenotype nor trisomy-9 itself had direct selective value under standard culture conditions. Mitochondrial nucleoid number was the same (50-100) in cells that had or had not experienced transient heteroplasmic instability, but 1-2 orders of magnitude less than the segregation number in such cells. These findings support the idea that mtDNA partition is under nuclear genetic control, and implicate a locus on chromosome 9 in this regulation.