Search PubMed⌕ Search

Biomedical subjects

H Tsukamoto

Publications and source records attributed to H Tsukamoto.

At least 91 records · Page 5Linked to original sources
PubMed1998

Identification of the 150-kDa surface antigen of Entamoeba histolytica as a galactose- and N-acetyl-D-galactosamine-inhibitable lectin.

A monoclonal antibody that reacts with a 150-kDa protein of Entamoeba histolytica on Western immunoblotting under nonreducing conditions inhibits the adherence and cytotoxicity of the ameba to mammalian cells in vitro. Affinity purification of solubilized trophozoites using the monoclonal antibody and electrophoresis yielded three glycoproteins with molecular masses of 150, 170, and 260 kDa, suggesting the existence of either a common epitope or the close association of these proteins. The 260-kDa fraction was identified as the well-known galactose (Gal)- and N-acetyl-D-galactosamine (GalNAc)-inhibitable lectin. The 150- and 170-kDa fractions seemed to exist as part of a 380-kDa native protein with an isoelectric point of pH 6.9. The N-terminal amino acid sequence of the 150-kDa protein was unique, indicating that the protein was not a degraded product of the 260-kDa lectin. By gel filtration, the 260-kDa lectin and the 150/170-kDa protein could be separated. When Chinese hamster ovary cells were pretreated with the fraction consisting of the 150/170-kDa protein the adherence of trophozoites to Chinese hamster ovary cells was competitively inhibited to a level equivalent to that observed for the 260-kDa lectin. The inhibitory effect was lost in the presence of Gal and GalNAc but was not influenced by the presence of glucose. These results demonstrate that the 150/170-kDa protein is a Gal/GalNAc-inhibitable lectin. The existence of a sugar-binding domain in the protein was confirmed by Gal-affinity chromatography.

Acetylgalactosamine↗
PubMed1998

Drug delivery of antisense molecules to the brain for treatment of Alzheimer's disease and cerebral AIDS.

Antisense oligonucleotides (ODNs) and peptide nucleic acids (PNAs) are potential therapeutics for eradication of malignancies, viral infections, and other pathologies. However, ODNs and PNAs in general are unable to cross cellular membranes and blood-tissue barriers, such as the blood-brain barrier (BBB), which is only permeable to lipophilic molecules of molecular weight <600 Da. Cellular delivery systems based on conjugates of streptavidin (SA) and the OX26 monoclonal antibody directed to the transferrin receptor may be employed as a universal carrier for the transport of mono-biotinylated peptides, ODNs, or PNAs. 3'-Biotinylation of phosphodiester (PO)-ODN produces complete protection of ODN against serum and cellular 3'-exonucleases, facilitating the conjugation to avidin-based delivery systems and maintaining the activation of RNase H. These delivery systems markedly increased the cellular uptake and antisense efficacy of 3'-biotinylated ODNs in models of Alzheimer's disease and HIV-AIDS. In vivo brain delivery studies demonstrated that 3'-protected PO-ODNs and PO-phosphorothioate(PS)-ODN hybrids containing a single PO linkage are subjected to endonuclease degradation in vivo. On the contrary PS-ODNs, which were also protected at 3'-terminus by biotinylation, are metabolically stable in vivo and resistant to exo/endonuclease degradation. However, because of the strong binding of these oligomers to plasma protein, PS-ODNs are poorly transported into the brain through the BBB by the OX26-SA delivery vector following intravenous administration. PNAs are also resistant to exo/endonuclease and protease degradation, and these molecules biotinylated at the amino terminal group were transported into the brain by the OX26-SA delivery system with brain uptake levels comparable to that of morphine. Using the rev gene of HIV as a model target, RNase protection assays and cell-free translation arrest showed that the PNA-OX26-SA conjugate maintained active recognition and inactivation of target mRNA, respectively. The overall experimental evidence suggests that PNA-OX26-SA conjugates represent optimal antisense molecules for drug delivery to the brain.

AIDS Dementia Complex↗
PubMed1998

Arg260-Cys mutation in severe factor XIII deficiency: conformational change of the A subunit is predicted by molecular modelling and mechanics.

To explore the implications of the structure/ function relationships in factor XIII. a patient with severe A subunit deficiency was examined at the DNA and RNA levels. Nucleotide sequence analysis of the patient's DNA amplified by PCR revealed that the patient had a replacement of C by T in the codon for Arg260. RT-PCR analysis demonstrated that only one kind of mRNA coding for the Arg260-Cys mutation was expressed in the patient at a normal level. Another possible defective allele of the A subunit gene with a G-A polymorphism was not expressed (null allele). The substitution of Arg260 by Cys located on the interface of two A subunits would preclude the reciprocal ionic interaction (salt bridge) between Arg260 and Asp404. Molecular modelling and, for the first time, molecular mechanics calculated that Cys260 changed the local conformation of the A subunit and reduced the electrostatic interaction between two monomers, suggesting destabilization of the molecule's dimer.

Amino Acid Substitution↗
PubMed1998

Evaluation of 9-cis retinoic acid for a new remedy of human retinoblastoma.

We investigated the effect of two isomers of retinoic acid (RA), all-trans RA and 9-cis RA, on the proliferation of Y79 human retinoblastoma cells. The two isomers inhibited the cell proliferation in a concentration-dependent manner. The IC50 for this inhibition by all-trans RA and 9-cis RA was 1.50 and 0.15 microM, respectively. The inhibitory effect of 9-cis RA on Y79 cell growth was observed within 24 hr, thereafter the cell number was gradually decreased. In contrast, no inhibition by all-trans RA of Y79 cell growth was observed within 24 hr, thereafter the cell number was slightly increased. In these cases, the cell viability at 4 days after the addition of 9-cis RA and all-trans RA was more than 90% and 95%, respectively. These results indicate that the two RA inhibit the proliferation of Y79 human retinoblastoma cells without inducing the cell death and that the effect of 9-cis RA on the inhibition of Y79 cell growth is much greater than that of all-trans RA.

Alitretinoin↗
PubMed1998

WY-14 643 rapidly activates nuclear factor kappaB in Kupffer cells before hepatocytes.

Stimulation of cell proliferation caused by peroxisome proliferators was blocked by antibodies against TNF alpha and agents that inactivate Kupffer cells, a rich source of TNF alpha, which supports the hypothesis that Kupffer cells play a pivotal role in peroxisome proliferator-induced hyperplasia. Here, the ability of the very potent peroxisome proliferator WY-14 643 to activate the transcription factor NF-kappaB in rat liver was examined since it is involved in TNF alpha production. Female Sprague-Dawley rats were treated by gavage with WY-14 643 (100 mg/kg) while control animals were given equivalent doses of vehicle (olive oil). Activation of NF-kappaB in both whole liver, non-parenchymal cells, Kupffer cells and hepatocytes was assessed for up to 36 h using an electrophoretic mobility shift assay. In whole liver, WY-14 643 transiently increased NF-kappaB binding maximally 3.5-fold in 2-8 h followed by a steady decline to near control levels at 36 h. As early as 2 h after WY-14 643 treatment, the active form of NF-kappaB was localized predominantly in Kupffer cells with values 20- to 25-times greater than in hepatocytes. In hepatocytes, a small increase in NF-kappaB binding was observed but only 8 h after WY-14 643 administration. Pre-treatment with allopurinol, a xanthine oxidase inhibitor and free radical scavenger, suppressed NF-kappaB activation by WY-14 643 almost completely. It is concluded that NF-kappaB is activated by reactive oxygen species and plays a central role in the mechanism of action of peroxisome proliferators. Moreover, these findings support the hypothesis that Kupffer cells play a pivotal role in peroxisome proliferator-induced hepatocyte proliferation through rapid NF-kappaB activation and subsequent induction of TNF alpha production. TNF alpha from Kupffer cells stimulates growth in parenchymal cells later via mechanisms that also involve NF-kappaB.

Allopurinol↗
PubMed1998

Low levels of apoptosis and proliferative activity in colorectal villous tumors: comparison with tubular tumors.

In order to clarify the cell kinetics of colorectal villous tumors (VT), 21 villous adenomatous areas and 12 carcinomatous areas within villous adenomas were investigated for proliferative activity and apoptosis and compared with a series of 41 tubular tumors (TT), demonstrating elements of intramucosal carcinomas as well as tubular adenomas (so-called carcinoma in tubular adenoma). Proliferation was estimated in terms of Ki-67 labeling indices and mitotic indices, and apoptosis was assessed by DNA nick-end labeling to give apoptotic indices. Apoptotic indices of villous adenomatous and carcinomatous regions were significantly lower than the values for their tubular counterparts. Ki-67 labeling indices were also significantly lower for adenoma components. Apoptotic indices, Ki-67 labeling indices and mitotic indices increased with atypia raised in tubular adenoma components. Correlations of mitotic indices with apoptotic indices, Ki-67 labeling indices with apoptotic indices and mitotic indices with Ki-67 labeling indices were found for each villous tumor group and tubular tumor group, and the apoptosis and proliferation ratios for villous tumors were relatively low, suggesting a tendency for greater growth due to less cell deletion. Although this is only one of the biological features of villous tumor groups, it might play a major role in generation of malignancy.

Adenocarcinoma↗
PubMed1998

[Risk factors for sudden death during hospitalization].

To determine the risk factors for sudden deaths in hospitalized patients, 209 patients (103 men and 106 women, age 76.7 +/- 12.6 years old, mean +/- S.D.) who died in 1996 were divided into two groups and their records were analyzed. One group, the sudden death group (SD), consisted of 16 patients who had stayed in the hospital for 2 weeks or more before the onset of symptoms that led to death within 24 hours. Those who died more than 24 hours after symptoms began were placed into the non-sudden death group (NSD). Fourteen patients who died within 2 weeks of admission were not analyzed in this study. Comparing the data of the two groups led to the following findings. First, the major causes of death in the SD group were exacerbation of chronic cardiac failure (5 cases), acute cardiac failure (2 cases), exacerbation of chronic respiratory failure (2 cases) and acute respiratory failure (2 cases). Second, patients in the SD group were significantly older than those in the NSD group, and had significantly more prescriptions for digitalis. Third, patients in the SD group had higher levels of hemoglobin and hematocrit, lower levels of BUN and a higher cardiothoracic ratio. Fourth, patients in the SD group had a higher incidence of ST abnormalities and T wave abnormalities in their electrocardiograms. Brugada syndrome or long QT syndrome were not seen in either group. Taken together, these findings suggest that aged patients with cardiac failure and myocardial ischemia may be at higher risk of sudden death.

Aged↗
PubMed1997

Expression of bcl-2 protein in esophageal squamous cell carcinomas and its association with lymph node metastasis.

BACKGROUND: Recent studies on the role of bcl-2 in malignant tumors have suggested its prognostic significance. The goals of the current study were to determine any correlation between bcl-2 expression in esophageal squamous cell carcinoma and histopathology, lymph node metastasis, and clinical variables, and to assess its applicability as a parameter for prognosis. METHODS: Immunohistochemical staining for bcl-2 (clone 124) was performed on archival material from 105 esophageal squamous cell carcinomas. The results were compared among patient subgroups. RESULTS: bcl-2 was expressed in 58% of esophageal carcinomas, demonstrating positive correlations with a lack of keratinization and an early stage of disease. Lymph node metastasis was significantly less frequently observed in the subset of early stage carcinomas with bcl-2 staining. Univariate analysis revealed significantly longer disease free survival in patients with bcl-2 positive carcinomas than in those bcl-2 negative. bcl-2 expression did not have independent prognostic value in a multivariate survival analysis. CONCLUSIONS: bcl-2 is frequently expressed in esophageal carcinomas, and this expression is positively associated with nonkeratinization and an early stage, whereas it is negatively linked with lymph node metastasis and may indicate a favorable prognosis.

Carcinoma, Squamous Cell↗
PubMed1997

Alanine exchanges of polar amino acids in the transmembrane domains of a platelet-activating factor receptor generate both constitutively active and inactive mutants.

To determine ligand-binding sites of a platelet-activating factor (PAF) receptor, alanine-scanning mutagenesis was carried out. All 23 polar amino acids in the putative 7-transmembrane (TM) domains of a guinea pig PAF receptor were individually replaced with alanine. The ligand-binding properties of mutant receptors were determined after transient expression in COS-7 cells. Mutants in TM II (N58A, D63A), TM III (N100A, T101A, S104A) and TM VII (D289A) displayed higher PAF-binding affinities than seen with the wild-type receptor. In contrast, mutants in TM V (H188A), TM VI (H248A, H249A, Q252A), and TM VII (Q276A, T278A) showed lower affinities. Representative mutants were then stably expressed in Chinese hamster ovary cells to observe PAF-induced cellular signals (arachidonate release, phosphatidylinositol hydrolysis, adenylyl cyclase inhibition). An N100A mutant with the highest affinity was constitutively active and was responsive to lyso-PAF, an inactive derivative of PAF. One nanomolar PAF induced no signals in low affinity mutants, an EC50 value for the wild-type receptor. Three histidines (His-188, His-248, His-249) might form a binding pocket for the phosphate group of PAF, since zinc effectively inhibited ligand binding. Based on these results, a three-dimensional molecular model of PAF and its receptor was generated using bacteriorhodopsin as a reference protein.

Alanine↗
PubMed1997

Iron overload in the rat pancreas following portacaval shunting and dietary iron supplementation.

Reproduction of pancreatic iron overload in an animal model has been difficult to achieve primarily because of the first-pass extraction of iron by the liver. We hypothesized that portacaval shunting would avoid this hepatic phenomenon and increase pancreatic iron deposition. An end-to-side portacaval shunt was surgically created in male Sprague-Dawley rats, and they were subsequently fed a carbonyl iron-supplemented diet for 17 weeks. This resulted in marked iron accumulation in the pancreas (1621 +/- 188 micrograms/g) compared to minimal deposition in sham-operated rats fed the same diet (138 +/- 53 micrograms/g). Iron deposition in the acinar and centroacinar cells was confirmed histologically by Gomori staining, as well as by ultrastructural examination. Iron overloading was associated with enhanced oxidative stress evidenced by a twofold increase in the levels of glutathione disulfide and thiobarbituric acid-reactive substances. Also, adducts of proteins with malondialdehyde and 4-hydroxynonenal were demonstrated in acinar and ductal cells. Other apparent consequences of iron overload were a 50% reduction in pancreatic amylase content and a decrease in pancreatic protein concentration. These hypotrophic changes were associated with a reduced mass of zymogen granules in the acinar cells noted histologically. Our results show that a combination of portacaval shunting and carbonyl iron feeding achieve pancreatic iron overload and support the role of oxidative stress in the pathogenesis of iron-induced damage in the pancreas.

Aldehydes↗
PubMed1997

Site-directed deletion of a 10-nucleotide domain of the 3'-untranslated region of the GLUT1 glucose transporter mRNA eliminates cytosolic protein binding in human brain tumors and induction of reporter gene expression.

The posttranscriptional regulation of GLUT1 glucose transporter gene expression may be mediated by specific interactions between cytosolic trans-acting factors and regulatory cis-elements within the 3'-untranslated regions (UTRs) of the GLUT1 mRNA. Recent studies demonstrate that experimental and human brain tumors express an 80-kDa protein that reacts with a specific sequence around nucleotide 2,200 within the GLUT1 mRNA 3'-UTR. The 80-kDa protein is selectively expressed in hemangioblastoma, a tumor characterized by overexpression of GLUT1. The enhancer role of this GLUT1 3'-UTR cis-element was confirmed in the present studies using the luciferase expression vector pGL2 and site-directed deletion. Transfection of C6 glioma cells with pGL2 (containing nucleotides 2,100-2,300 of the bovine GLUT1 3'-UTR inserted at the Pfl MI site within the luciferase 3'-UTR) results in a fivefold increase in luciferase gene expression. Deletion of nucleotides 2,181-2,190 of the bovine GLUT1 3'-UTR, i.e., the putative binding site of the 80-kDa protein, completely eliminated the enhancement of luciferase activity in the transfected cells. Luciferase mRNA containing the putative cis-element inserted in the 3'-UTR was transcribed, and after UV crosslinking, this mRNA complexed with the 80-kDa protein in cytosol of either C6 cells or hemangioblastoma. In contrast, this complex was undetected with either luciferase control mRNA or 10 nucleotide-deleted RNA. The present study provides evidence that nucleotides 2,181-2,190 of the bovine GLUT1 mRNA 3'-UTR forms a complex with brain tumor cytosolic proteins that serves to increase GLUT1 gene expression at the posttranscriptional level.

Animals↗
PubMed1997

Diminished retinoic acid signaling in hepatic stellate cells in cholestatic liver fibrosis.

Hepatic stellate cells (HSC) participate in liver fibrogenesis via myofibroblastic activation, the extent of which appears to correlate with the loss of cellular vitamin A. The present study has tested a hypothesis that HSC activation is associated with diminished retinoic acid (RA) signaling. Pure HSC were isolated from rats with cholestatic liver fibrosis induced by bile duct ligation (BDL) and sham-operated animals (Sham). Northern blot analysis of HSC RNA from BDL confirmed fibrogenic activation of the cells with enhanced mRNA levels for procollagen-alpha1(I) and transforming growth factor-beta1 (TGF-beta1). Competitive polymerase chain reaction analysis showed selective reductions in the mRNA levels of RA receptor (RAR)-beta and retinoid X receptor (RXR)-alpha to 20 and 17% of the Sham HSC. The mRNA level for cellular retinol binding protein I, a gene with RA responsive element (RARE), was also suppressed by 78% in BDL. The concentrations of all-trans-RA and 9-cis-RA were decreased in HSC from BDL. Nuclear extracts of these cells showed diminished binding activity to the RARE, whereas activity of AP-1, a transcription factor known to be antagonized by RAR and RXR, was enhanced. These results demonstrate diminished RA signaling in HSC from cholestatic liver fibrosis, which appeared to have resulted from RA deficiency and suppressed expression of RAR-beta and RXR-alpha. Furthermore, the reciprocal enhancement of AP-1 activity and coordinately increased expression of an AP-1 responsive gene, TGF-beta1, suggest a permissive role of the diminished RA signaling in promoting AP-1 activity and TGF-beta1 expression.

Animals↗
PubMed1997

Role of iron in NF-kappa B activation and cytokine gene expression by rat hepatic macrophages.

A redox-sensitive nuclear factor, NF-kappa B, induces transcription of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in macrophages. The present study has investigated the role of iron in NF-kappa B activation and TNF-alpha and IL-6 expression by rat hepatic macrophages (HM). As an in vivo model, cholestatic liver injury was induced in rats by ligation of the common bile duct (BDL). During the first 2 wk after BDL, there was an increase in the hepatic level of thiobarbituric acid-reactive substances (TBARS) that was accompanied by the appearance of protein-malondialdehyde adducts in the periportal region. This increase was reduced after 3 wk. TNF-alpha and IL-6 mRNA levels in HM from the BDL rats were increased at 1 and 2 wk and attenuated at 3 wk. Gel mobility shift assay of HM nuclear extracts demonstrated the similar temporal pattern of enhanced NF-kappa B binding activity. Treatment of the BDL animals with 1,2-dimethyl-3-hydroxypyrid-4-one (L-1), a lipophilic iron chelator, suppressed the increases in hepatic TBARS by 64%, plasma alanine aminotransferase by 45%, and HM TNF-alpha and IL-6 mRNA by > 84%. Concomitantly, the HM NF-kappa B binding activity was reduced close to the level observed in sham-operated rats. Treatment of cultured HM with L-1 also blocked lipopolysaccharide-stimulated NF-kappa B activation and TNF-alpha and IL-6 expression at mRNA and protein levels. These results demonstrate that the iron chelator effectively blocks NF-kappa B activation and coordinate TNF-alpha and IL-6 gene upregulation by HM in cholestatic liver injury or under in vitro lipopolysaccharide stimulation. These findings support a pivotal role for iron in activation of NF-kappa B and cytokine gene expression by HM in vitro and in vivo.

Animals↗
PubMed1996

Differential expression in glioblastoma multiforme and cerebral hemangioblastoma of cytoplasmic proteins that bind two different domains within the 3'-untranslated region of the human glucose transporter 1 (GLUT1) messenger RNA.

The glucose transporter 1 (GLUT1) protein is underexpressed in human glioblastoma multiforme and is overexpressed in human cerebral hemangioblastoma. To gain in-sight into possible posttranscriptional mechanisms regulating the expression of the GLUT1 protein in human brain tumors, cytosolic proteins were prepared from these two tumors and used in RNase T1 protection assays that employed [32P]human GLUT1 synthetic RNA prepared from transcription plasmids. Gel shift mobility assays and ultra-violet light cross-linking studies demonstrated the formation of specific RNA/protein complexes that migrated with a mol mass of 120, 44, and 41 kD. RNase T1 mapping and oligodeoxynucleotide competition studies showed that the 120 kD complex was comprised of an RNA fragment that localized to nucleotides 2186-2203 of the GLUT1 mRNA. The 44 kD complex contained an adenosine-uridine-rich RNA fragment that localized to nucleotides 1885-1906 of the human GLUT1 mRNA, and the formation of this complex was inhibited by synthetic RNA enriched in adenosine-uridine sequences. The 44 kD complex was selectively downregulated in hemangioblastoma as compared to glioblastoma multiforme. These studies demonstrate that human brain tumors have differential regulation of cytosolic proteins that specifically interact with two different domains in the 3'-untranslated region of the GLUT1 mRNA, which may serve to mediate the posttranscriptional regulation of GLUT1 gene expression in these tumors.

Base Sequence↗
PubMed1996

Down-regulation of secretion of human complement component C2 by the product of an alternatively spliced C2 messenger RNA.

We have previously described alternatively spliced transcripts of the human C2 gene. Among those, C2delta(17), in which exon 17 has been spliced out, encodes a polypeptide that contains the C4b binding and the CIs cleavage sites of C2, but lacks the serine protease active center. To study the possible function of this variant, we constructed C2delta(17) cDNA by deletional mutagenesis and expressed it transiently in COS cells. Transfected COS cells secreted only trace amounts of the C2delta(17) polypeptide, which had no detectable hemolytic activity and could not be cleaved by CIs. Pulse-chase experiments using [35S]methionine demonstrated that the majority of the 88-kDa C2delta(17) remained intracellular. Control wild-type (wt) C2 in the intracellular compartment consisted of two bands of 93 and 99 kDa, the latter corresponding to mature secreted C2. Intracellular C2delta(17) and only the 93-kDa wt C2 were sensitive to endoglycosidase H, a marker for transport from the endoplasmic reticulum (ER) to the Golgi. Experiments using brefeldin A and double label immunofluorescence staining indicated that C2delta(17) exhibited a typical ER distribution pattern, while wt C2 accumulated in the ER-Golgi intermediate compartment. Secretion of C2 by COS cells cotransfected with wt C2 and C2delta(17) cDNA was significantly decreased compared with that by cells transfected with wt C2 alone. These combined results indicate that C2delta(17) is retained in the ER probably because it is incorrectly folded and that it could down-regulate the expression of the wt C2 gene.

Alternative Splicing↗
PubMed1996

Giant mitochondria induced in rat pancreatic exocrine cells by ethanol and iron.

BACKGROUND: Mitochondria are sensitive indicators of cellular pathology. Under certain circumstances, these organelles respond to cellular insult by a marked increase in size, resulting in the formation of giant mitochondria (megamitochondria). Ethanol has been implicated in the induction of giant mitochondria in rat hepatocytes. Since ethanol is reported to affect pancreatic mitochondria, we examined this organ for evidence of mitochondrial giantism in rats administered ethanol and a relatively small amount of supplementary iron. METHODS: Diets were administered via a chronically implanted gastrostomy catheter. Rats were segregated in four groups: 1) basic high-fat diet, 2) ethanol and a high fat diet, 3) carbonyl iron and a high-fat diet, and 4) ethanol and carbonyl iron combined with a high-fat diet. After the animals were on their respective diets for 16 weeks, specimens of pancreas were extirpated and processed for and examined by transmission electron microscopy. RESULTS: Mitochondria in rats on the basic high fat diet resemble those in untreated controls. With ethanol and a high-fat diet, some mitochondria in virtually every exocrine cell are profoundly altered. Such organelles, which are of normal size, have undergone rearrangement of their internal membranes, with three of four parallel cristae residing at one or both poles of spherical to ovate mitochondria. In rats receiving both ethanol and carbonyl iron, giant mitochondria are present in pancreatic exocrine cells. Except for their size, megamitochondria in many cases are virtual likenesses of the altered mitochondria in the alcohol-high-fat rats, having several stacked cristae at either pole and an enhanced matrix compartment. Many of the giant mitochondria have at least one expanded crista, which contains packets of helically coiled filaments. When control rats are fed carbonyl iron without ethanol, the pancreatic mitochondria display a marked propensity for forming clusters of tightly interlocked organelles, formations that may be a prelude to mitochondrial fusion. CONCLUSIONS: It appears that iron supplementation sets the stage for organelle fusion, hence enlargement, with the ethanol providing the stimulus for fusion to actually take place, and controlling the final morphology of the resultant megamitochondria.

Animals↗