Pielonefritis xantogranulomatosa: un reto actual para la laparoscopia.

OBJECTIVE: To present the results of our case series on laparoscopic nephrectomy in xanthogranulomatous pyelonephritis (XGP). METHODS: A retrospective study was conducted that included 143 patients treated with laparoscopic nephrectomy for non-functioning kidney, of whom 15 had XGP, within the time frame of 2011 to 2019. The demographic and clinical data were collected, along with the intraoperative results, complications, and days of hospital stay. RESULTS: Transperitoneal laparoscopic nephrectomy was successfully performed on 15 patients with XGP, with no need for conversion. Mean intraoperative time was 124.4 minutes (range 70-240) and intraoperative blood loss was 148.5 ml (range 30-550), with no blood transfusion required. No intraoperative complications occurred but there was one postoperative complication (6.6%), classified as Clavien-Dindo I (surgical wound infection). Mean hospital stay was 2.85 days (range 2-7). CONCLUSIONS: Nephrectomy is the definitive management for XGP, and the laparoscopic approach should be considered a treatment modality, despite the fact that the pathology involves a severe chronic inflammatory process. Its benefits are reduced surgery duration, less blood loss, a lower complication rate, and fewer days of hospital stay, when performed by a skilled and experienced surgeon.

OBJETIVO: Presentar los resultados de nuestra serie de nefrectomía laparoscópica en pielonefritis xantogranulomatosa (PXG). MÉTODO: Se realizó un estudio retrospectivo que incluyó 143 pacientes tratados con nefrectomía laparoscópica por exclusión renal, de los cuales 15 fueron por PXG, en el periodo comprendido de 2011 a 2019. Se recolectaron datos demográficos y clínicos, resultados transoperatorios, complicaciones y días de estancia hospitalaria. RESULTADOS: Se realizó nefrectomía laparoscópica transperitoneal de forma exitosa en 15 pacientes con PXG, sin necesidad de conversión. El tiempo transoperatorio promedio fue de 124.4 minutos (rango: 70-240). El sangrado transoperatorio fue de 148.5 ml (rango: 30-550), sin requerimiento de transfusión sanguínea. No se reportaron complicaciones transoperatorias; se presentó una complicación en el posoperatorio (6.6%) clasificada como Clavien-Dindo I (infección de la herida quirúrgica). La estancia hospitalaria promedio fue de 2.85 días (rango: 2-7). CONCLUSIONES: El manejo definitivo de la PXG es la nefrectomía, y el abordaje laparoscópico debe ser considerado como una modalidad de tratamiento a pesar de ser una patología que presenta un proceso inflamatorio grave y crónico, obteniéndose beneficios como disminución en el tiempo quirúrgico, menor sangrado, menor tasa de complicaciones y menos días de estancia hospitalaria cuando es realizado por un cirujano experimentado.

Advantages and Short-Term Outcomes of Laparoscopic-Assisted Renal Surgery in Elderly Patients.

OBJECTIVE: To compare the perioperative results of adult and elderly patients undergoing laparoscopic renal surgery. METHODOLOGY: Retrospective, analytical study. 448 who underwent kidney surgery for benign or malignant pathologies between 2011-2019 were included in the General Hospital of Mexico "Dr. Eduardo Liceaga". They were categorized into two groups: Group 1 <60 years and Group 2 >60 years. Descriptive statistics and bivariate analysis were performed, the calculations were performed with 95% reliability and a value of p (<0.05). RESULTS: In the group over 60 years of age, the following was found: Age: 67.1 years (60-83). IMC 28.3 kg/m2 (19-48.7). Intra and postsurgical outcomes: intraoperative bleeding = 184.4cc (5-1700). Surgical Time = 112.6min (30-240). Days of hospital stay = 2 (1-7). Complications in 2.6% (Clavien-Dindo: I = 2; II = 1), no conversion was required in any patient. There were no statistically significant differences with group 1, an exception for intraoperative bleeding. CONCLUSIONS: Our study is a pioneer in Latin America in the evaluation of the geriatric population and outcomes with laparoscopic surgery and we recommend that renal procedures with a laparoscopic approach should be considered as the best strategy in the management of benign or malignant renal pathology in geriatric patients.

Oncological and functional results after robot-assisted radical prostatectomy in high-risk prostate cancer patients.

BACKGROUND: Pentafecta is currently the standard in the comprehensive evaluation of patients undergoing radical prostatectomy, the objective of this study is the evaluation of oncological and functional outcomes in patients with prostate cancer of high risk undergoing robot-assisted radical prostatectomy. METHOD: Descriptive, retrospective study of 20 cases with a diagnosis of high-risk prostate cancer. The high-risk group is composed of a prostate-specific antigen equal or greater than 20 ng/mL, Gleason score equal or greater than 8, or clinical stages T2/T3 treated with robotic approach. RESULTS: Biochemical control was achieved from the first six weeks after the surgical event. 75% (n = 15) had negative surgical margins. 100% of the patients (n = 20) presented urinary continence immediately after removal of the urinary catheter. Erectile function was preserved at 3, 6 and 12 months in 100% of the patients who underwent neuropreservation but with use of an PDE inhibitor. (n = 5). Complications were reported in 10% (Clavien-Dindo I-II). CONCLUSIONS: Robot-assisted radical prostatectomy in patients with high-risk prostate cancer is considered an appropriate treatment option in selected patients. A different experimental design is needed to define the advantages or disadvantages of this approach, as well as to determine its role and application in clinical practice.

ANTECEDENTES: Pentafecta es el estándar en la evaluación integral de los pacientes sometidos a prostatectomía radical. El objetivo de este estudio es evaluar y describir los desenlaces oncológicos y funcionales en pacientes con cáncer de próstata de alto riesgo sometidos a prostatectomía radical asistida por robot. MÉTODO: Estudio descriptivo, retrospectivo, de 20 pacientes con diagnóstico de cáncer de próstata de alto riesgo. El grupo de alto riesgo se compone por pacientes con antígeno prostático específico mayo o igual a 20 ng/ml, reporte histopatológico con Gleason mayor o igual a 8 y/o estadios clínicos T2/T3 tratados con abordaje robótico. RESULTADOS: El control bioquímico se alcanzó a partir de las primeras 6 semanas posterior al evento quirúrgico. El 75% (n = 15) presentaron márgenes quirúrgicos negativos. El 100% de los pacientes (n = 20) presentaron continencia urinaria inmediatamente después del retiro de la sonda vesical. La función eréctil se conservó a 3, 6 y 12 meses en el 100% de los pacientes a los que se realizó neuropreservación, pero con uso de inhibidor de la fosfodiesterasa (n = 5). Se reportaron complicaciones en el 10% de los casos (Clavien-Dindo I-II). CONCLUSIONES: La prostatectomía radical asistida por robot en pacientes con cáncer de próstata de alto riesgo se considera una opción de tratamiento adecuada en casos seleccionados. Se necesita un diseño experimental distinto para definir las ventajas o desventajas de este abordaje, así como determinar su papel y aplicación en la práctica clínica.

Single-port versus multiport robotic-assisted radical prostatectomy: A systematic review and meta-analysis on the da Vinci SP platform.

CONTEXT: Prostate cancer is the most common cancer in men; robotic prostatectomy has cemented itself as part of the standard of care. Since its approval by the Food and Drug Administration in 2018, the SP console's application has been increasingly studied and compared with the multiport (MP) robotic approach. METHODS: Following PRISMA guidelines and PROSPERO registration CRD42021228744, a systematic review was performed in April 2021 on single-port robotic-assisted radical prostatectomies (SP-RARPs) compared to MP. Outcomes of interest were operative time, bleeding, complications, analgesic use, and postoperative continence, and erectile function. Data were analyzed with Review Manager 5.3. RESULTS: Seven studies were included, of which six studies met the inclusion criteria for quantitative synthesis, totalling 1068 patients, out of which 324 underwent SP-RARP and 744 underwent MP-RARP. No differences were found in baseline characteristics such as age, body mass index, prostatic-specific antigen, or stage. No differences in blood loss-15.77 mL [-42.44, 10.89], p = 0.25, operative time 3.93 min [-4.12, 11.98], p = 0.34, or positive surgical margins, with an odds ratio (OR) of 0.78 [0.55, 1.10], p = 0.15-were found. Length of stay was significantly shorter in SP -0.94 days [-1.56, -0.33], p = 0.003, with no differences in complication rates, with an OR of 1.29 [0.78, 2.14], p = 0.32, continence rates, with an OR of 1.29 [0.90, 1.83], p = 0.16, erectile function, with an OR of 0.86 [0.52, 1.40], p = 0.54, or biochemical recurrence. Qualitative evidence suggests decreased opioid consumption. CONCLUSION: SP-RARPs are feasible alternatives to the traditional MP with possible benefits in pain management and length of stay. Future high-quality studies are needed to confirm these findings.

Liver injury correlates with biomarkers of autoimmunity and disease activity and represents an organ system involvement in patients with systemic lupus erythematosus.

Liver disease (LD), defined as ≥ 2-fold elevation of aspartate aminotransferase (AST) or alanine aminotransferase (ALT), was examined in a longitudinal study of systemic lupus erythematosus (SLE) patients. Among 435 patients, 90 (20.7%) had LD with a greater prevalence in males (15/39; 38.5%) than females (75/396; 18.9%; p = 0.01). SLE disease activity index (SLEDAI) was greater in LD patients (7.8 ± 0.7) relative to those without (5.8 ± 0.3; p = 0.0025). Anti-smooth muscle antibodies, anti-DNA antibodies, hypocomplementemia, proteinuria, leucopenia, thrombocytopenia, and anti-phospholipid syndrome were increased in LD. An absence of LD was noted in patients receiving rapamycin relative to azathioprine, cyclosporine A, or cyclophosphamide. An absence of LD was also noted in patients treated with N-acetylcysteine. LFTs were normalized and SLEDAI was diminished with increased prednisone use in 76/90 LD patients over 12.1 ± 2.6 months. Thus, LD is attributed to autoimmunity and disease activity, it responds to prednisone, and it is potentially preventable by rapamycin or N-acetylcysteine treatment.

N-acetylcysteine reduces disease activity by blocking mammalian target of rapamycin in T cells from systemic lupus erythematosus patients: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Systemic lupus erythematosus (SLE) patients exhibit T cell dysfunction, which can be regulated through mitochondrial transmembrane potential (Δψm) and mammalian target of rapamycin (mTOR) by glutathione (GSH). This randomized, double-blind, placebo-controlled study was undertaken to examine the safety, tolerance, and efficacy of the GSH precursor N-acetylcysteine (NAC). METHODS: A total of 36 SLE patients received either daily placebo or 1.2 gm, 2.4 gm, or 4.8 gm of NAC. Disease activity was evaluated monthly by the British Isles Lupus Assessment Group (BILAG) index, the SLE Disease Activity Index (SLEDAI), and the Fatigue Assessment Scale (FAS) before, during, and after a 3-month treatment period. Mitochondrial transmembrane potential and mTOR were assessed by flow cytometry. Forty-two healthy subjects matched to patients for age, sex, and ethnicity were studied as controls. RESULTS: NAC up to 2.4 gm/day was tolerated by all patients, while 33% of those receiving 4.8 gm/day had reversible nausea. Placebo or NAC 1.2 gm/day did not influence disease activity. Considered together, 2.4 gm and 4.8 gm NAC reduced the SLEDAI score after 1 month (P = 0.0007), 2 months (P = 0.0009), 3 months (P = 0.0030), and 4 months (P = 0.0046); the BILAG score after 1 month (P = 0.029) and 3 months (P = 0.009); and the FAS score after 2 months (P = 0.0006) and 3 months (P = 0.005). NAC increased Δψm (P = 0.0001) in all T cells, profoundly reduced mTOR activity (P = 0.0009), enhanced apoptosis (P = 0.0004), reversed expansion of CD4-CD8- T cells (mean ± SEM 1.35 ± 0.12-fold change; P = 0.008), stimulated FoxP3 expression in CD4+CD25+ T cells (P = 0.045), and reduced anti-DNA production (P = 0.049). CONCLUSION: This pilot study suggests that NAC safely improves lupus disease activity by blocking mTOR in T lymphocytes.

Light microscopic methods to visualize mitochondria on tissue sections.

Mitochondria are cytoplasmic, double-membrane organelles, a main role of which is to synthesize ATP, the universal energy 'supply' of cells. In the last three decades, molecular genetic, biochemical, immunological and cell biological techniques have been applied in a coordinated fashion to unveil the pathogenesis of known mitochondrial disorders, as well as to explore the role of mitochondria in aging and neurodegenerative diseases. Once to be thought to be rare, it is now clear that mitochondrial dysfunction is an important cause of neurological and cardiac diseases, and age-related disorders such as cancer. Here, we review, illustrate, and provide updated protocols of two histochemical, and three immunohistochemical methods that in our opinion are the most reliable tools to visualize mitochondria on tissue sections from normal and disease specimens.

Fatal toxic myopathy attributed to propofol, methylprednisolone, and cyclosporine after prior exposure to colchicine and simvastatin.

We report a fatal case of toxic myopathy in a patient with a transplanted heart for severe ischemic coronary artery disease. He was on long-term cyclosporine, prednisone, and mycofenolate. Four months before the development of proximal muscle weakness, his simvastatin dose was doubled, and he was also started on colchicine for acute exacerbation of gout. He developed progressive muscle weakness leading to shortness of breath and hospitalization for respiratory failure. Colchicine and simvastatin were stopped on admission. He received high-dose methylprednisolone for continued muscle weakness while he was sedated with propofol. These changes led to a marked elevation of creatine kinase, peaking at 33,580 U/ml. The muscle biopsy revealed toxic vacuolization, mitochondrial damage, and no evidence of inflammation. Based on the timing of events, the combination of propofol, high-dose methylprednisolone, and cyclosporine have triggered rhabdomyolysis, which may have been facilitated by prior administration of colchicine and simvastatin.

Mitochondrial encephalomyopathy due to a novel mutation in the tRNAGlu of mitochondrial DNA.

A 14-year-old boy had exercise intolerance, weakness, ataxia, and lactic acidosis. Because his muscle biopsy showed a mosaic pattern of fibers staining intensely with the succinate dehydrogenase reaction but not at all with the cytochrome c oxidase reaction, we sequenced his mitochondrial DNA and found a novel mutation (C14680A) in the gene for tRNAGlu. The mutation was present in accessible tissues from the asymptomatic mother but not from a brother with Asperger syndrome. These data expand the clinical heterogeneity of mutations in this mitochondrial gene.

Mitochondrial myopathy associated with a novel mutation in mtDNA.

A 6-year-old boy had progressive muscle weakness since age 4 and emotional problems diagnosed as Asperger syndrome. His mother and two older siblings are in good health and there is no family history of neuromuscular disorders. Muscle biopsy showed ragged-red and cytochrome coxidase (COX)-negative fibers. Respiratory chain activities were reduced for all enzymes containing mtDNA-encoded subunits, especially COX. Sequence analysis of the 22 tRNA genes revealed a novel G10406A base substitution, which was heteroplasmic in multiple tissues of the patient by RFLP analysis (muscle, 96%; urinary sediment, 94%; cheek mucosa, 36%; blood, 29%). The mutation was not detected in any accessible tissues from his mother or siblings. It appears that this mutation arose de novo in the proband, probably early in embryogenesis.

Clinical spectrum of mitochondrial DNA depletion due to mutations in the thymidine kinase 2 gene.

BACKGROUND: Mitochondrial DNA depletion syndrome is an autosomal recessive disorder characterized by decreased mitochondrial DNA copy numbers in affected tissues. It has been linked to 4 genes involved in deoxyribonucleotide triphosphate metabolism: thymidine kinase 2 (TK2), deoxyguanosine kinase (DGUOK), polymerase gamma (POLG), and SUCLA2, the gene encoding the beta-subunit of the adenosine diphosphate-forming succinyl coenzyme A synthetase ligase. OBJECTIVE: To highlight the variability in the clinical spectrum of TK2-related mitochondrial DNA depletion syndrome. DESIGN: Review of patients and the literature. SETTING: Tertiary care university. PATIENTS: Four patients with mitochondrial DNA depletion syndrome and mutations in the TK2 gene. MAIN OUTCOME MEASURES: Definition of clinical variability. RESULTS: Patient 1 had evidence of lower motoneuron disease and was initially diagnosed as having spinal muscular atrophy type 3. Patient 2, who is alive and ambulatory at age 9 years, presented at age 2 years with a slowly progressive mitochondrial myopathy. Patient 3 had a more severe myopathy, with onset in infancy and death at age 6 years of respiratory failure. Patient 4 had a rapidly progressive congenital myopathy with rigid spine syndrome and he died at age 19 months. CONCLUSION: The clinical spectrum of TK2 mutations is not limited to severe infantile myopathy with motor regression and early death but includes spinal muscular atrophy type 3-like presentation, rigid spine syndrome, and subacute myopathy without motor regression and with longer survival.

Signaling abnormalities in systemic lupus erythematosus as potential drug targets.

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease characterized by T-cell, B-cell, and dendritic cell dysfunction and antinuclear autoantibody production. Much of the knowledge that has been gained about SLE in recent years is related to molecular signaling abnormalities present in the disease. Signaling through the T-cell receptor (TCR) is affected in SLE by alterations in the localization, amount, and activity of numerous protein kinases. TCR stimulation releases calcium from intracellular stores, which triggers an influx of extracellular calcium and activates the transcription of many genes, including interleukin-2. Short-term calcium fluxing is exaggerated in SLE, but long-term calcium fluxing is diminished and may account for sub-optimal interleukin-2 production. SLE T-cells have persistently hyperpolarized mitochondria associated with increased mitochondrial mass, high levels of reactive oxygen species (ROS) and low levels of ATP, which decrease activation-induced apoptosis and instead predispose T cells for necrosis, thus stimulating inflammation in SLE. The pentose phosphate pathway impacts the mitochondrial potential and represents a target for possible intervention. Nitric oxide (NO) is a potential link to tie together the signaling and mitochondrial abnormalities in SLE. NO-induced mitochondrial biogenesis recapitulates the TCR-stimulated calcium fluxing abnormalities of SLE T-cells. Since mitochondria can store calcium, the increase in mitochondrial mass may be implicated in the aberrant calcium fluxing in SLE T cells. The mammalian target of rapamycin senses the mitochondrial potential and regulates calcium release, serving as a novel target of treatment of SLE.

Unusual clinical presentations in four cases of Leigh disease, cytochrome C oxidase deficiency, and SURF1 gene mutations.

Mutations in the SURF1 gene are the most frequent causes of Leigh disease with cytochrome c oxidase deficiency. We describe four children with novel SURF1 mutations and unusual features: three had prominent renal symptoms and one had ragged red fibers in the muscle biopsy. We identified five pathogenic mutations in SURF1: two mutations were novel, an in-frame nonsense mutation (834G-->A) and an out-of-frame duplication (820-824dupTACAT). Although renal manifestations have not been described in association with SURF1 mutations, they can be part of the clinical presentation. Likewise, mitochondrial proliferation in muscle (with ragged red fibers) is most unusual in Leigh disease but might be part of an emerging phenotype.

Novel mitochondrial DNA ND5 mutation in a patient with clinical features of MELAS and MERRF.

BACKGROUND: The mitochondrial DNA gene encoding subunit 5 of complex I (ND5) has turned out to be a hot spot for mutations associated with mitochondrial encephalomyopathy with lactic acidosis and strokelike episodes (MELAS) and various overlap syndromes. OBJECTIVE: To describe a novel mutation in the ND5 gene in a young man man with an overlap syndrome of MELAS and myoclonus epilepsy with ragged-red fibers. DESIGN: Case report. PATIENT: A 25-year-old man had recurrent strokes, seizures, and myoclonus. His mother also had multiple strokes. A muscle biopsy specimen showed no ragged-red fibers but several strongly succinate dehydrogenase-reactive blood vessels. RESULTS: Biochemical analysis showed isolated complex I deficiency and molecular analysis revealed a novel heteroplasmic mutation (G13042A) in the ND5 gene. CONCLUSIONS: These data confirm that ND5 is a genetic hot spot for overlap syndromes, including MELAS and strokelike and myoclonus epilepsy with ragged-red fibers.

Congenital or late-onset myopathy in patients with the T14709C mtDNA mutation.

Three patients with different clinical phenotypes harbored the same point mutation at nucleotide 14709 (T14709C) in the tRNAGlu gene of mitochondrial DNA (mtDNA). The first patient was a 21-month-old child with severe congenital myopathy, respiratory distress and mild mental retardation. Muscle biopsy showed about 12% cytochrome c oxidase (COX)-negative ragged-red fibers (RRFs), and markedly decreased activities of mitochondrial respiratory chain complexes I, III and IV. The other two patients were 51- and 55-year-old siblings with slowly progressive myopathy and diabetes mellitus. Muscle biopsy showed focal COX-negative RRFs and decreased activities of complexes I, III and IV. In all three patients, the T14709C mutation was abundant in muscle but present at lower levels in accessible tissues. Previously described patients with the same mutation also showed congenital or late-onset myopathy. Diabetes is frequently associated with both phenotypes and is a clinical clue to the molecular diagnosis.

Phenolic content and antioxidant capacity of muscadine grapes.

Fruits of 10 cultivars of muscadine grapes (five bronze skin and five purple skin) grown in southern Georgia were separated into skin, seed, and pulp. Each fruit part and the leaves from the corresponding varieties were extracted for HPLC analysis of major phenolics. Total phenolics were determined colorimetrically using Folin-Ciocalteu reagent. Total anthocyanins were determined according to a pH-differential method, using a UV-visible spectrophotometer. Antioxidant capacity was determined by the Trolox equivalent antioxidant capacity (TEAC) assay. Gallic acid, (+)-catechin, and epicatechin were the major phenolics in seeds, with average values of 6.9, 558.4, and 1299.4 mg/100 g of fresh weight (FW), respectively. In the skins, ellagic acid, myricetin, quercetin, kaempferol, and trans-resveratrol were the major phenolics, with respective average values of 16.5, 8.4, 1.8, 0.6, and 0.1 mg/100 g of FW. Contrary to previous results, ellagic acid and not resveratrol was the major phenolic in muscadine grapes. The HPLC solvent system used coupled with fluorescence detection allowed separation of ellagic acid from resveratrol and detection of resveratrol. Reported here for the first time are the phenolic content and antioxidant capacity of muscadine leaves. Major phenolics in muscadine leaves were myricetin, ellagic acid, kaempferol, quercetin, and gallic acid, with average concentrations of 157.6, 66.7, 8.9, 9.8, and 8.6, respectively. Average total phenolics were 2178.8, 374.6, 23.8, and 351.6 mg/g gallic acid equivalent in seed, skin, pulp, and leaves, respectively. Total anthocyanin contents were 2.1 and 132.1 mg/100 g of FW in the skins of bronze and purple grapes, respectively, and 4.3 and 4.6 mg/100 g of FW in seeds and pulps, in that order. Antioxidant capacity values were, on average, 2.4, 12.8, 281.3, and 236.1 microM TEAC/g of FW for pulps, skins, seeds, and leaves, respectively.

Mitochondrial myopathy of childhood associated with mitochondrial DNA depletion and a homozygous mutation (T77M) in the TK2 gene.

BACKGROUND: The mitochondrial DNA depletion syndrome is an autosomal recessive disorder of infancy or childhood characterized by decreased mitochondrial DNA copy number in affected tissues. Mutations in 2 genes involved in deoxyribonucleotide metabolism, the deoxyguanosine kinase gene (DGK) and the thymidine kinase 2 gene (TK2), have been related to this syndrome. OBJECTIVE: To describe 3 siblings with the myopathic form of mitochondrial DNA depletion syndrome and a homozygous mutation in the TK2 gene. PATIENTS AND METHODS: These children developed normally until 12 to 16 months of age, when they started showing difficulty walking, which rapidly progressed to severe limb weakness. They died of respiratory failure between the ages of 23 and 40 months. Histochemical and biochemical studies of respiratory chain complexes were performed in muscle biopsy specimens. The whole coding region of the TK2 gene was sequenced. RESULTS: Muscle biopsy showed ragged-red cytochrome-c oxidase-negative fibers. All affected siblings had markedly decreased activities of respiratory chain complexes. Southern blot analysis showed severe reduction of the mitochondrial DNA-nuclear DNA ratio in muscle biopsy specimens from all patients, indicating 80% to 90% mitochondrial DNA depletion. Sequencing of the TK2 gene showed a homozygous C-->T transition at nucleotide 228 in exon 5, which changes a threonine to a methionine at position 77 (T77M). CONCLUSIONS: These results document the importance of screening the TK2 gene in patients with myopathic mitochondrial DNA depletion syndrome and confirm that exon 5 is a "hot spot" for TK2 mutations.

The A8344G mutation in mitochondrial DNA associated with stroke-like episodes and gastrointestinal dysfunction.

We report an unusual case of encephalo-entero-myopathy associated with the A8344G mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). This patient had mitochondrial myopathy, multiple lipomatosis, mild hearing loss, stroke-like episodes, and paralytic ileus, but she lacked the canonical clinical features of MERRF, myoclonus, epilepsy, or ataxia. We conducted genetic, biochemical, histochemical, and immunohistochemical studies in skeletal muscle, brain, intestine, and lipoma tissue. The mutation was abundant in all tissues, and cytochrome c oxidase (COX) activity was selectively decreased in brain and small intestine. COX deficiency was also documented histochemically and immunohistochemically in the small intestine, suggesting that mitochondrial dysfunction played a role in the pathogenesis of paralytic ileus. This case illustrates an unusual and dramatic clinical phenotype of the A8344G mutation, characterized by stroke-like episodes and acute ileus.

Identical mitochondrial DNA deletion in a woman with ocular myopathy and in her son with pearson syndrome.

Single deletions of mitochondrial DNA (mtDNA) are associated with three major clinical conditions: Kearns-Sayre syndrome, a multisystem disorder; Pearson syndrome (PS), a disorder of the hematopoietic system; and progressive external ophthalmoplegia (PEO), primarily affecting the ocular muscles. Typically, single mtDNA deletions are sporadic events, since the mothers, siblings, and offspring of affected individuals are unaffected. We studied a woman who presented with PEO, ptosis, and weakness of pharyngeal, facial, neck, and limb muscles. She had two unaffected children, but another of her children, an infant son, had sideroblastic anemia, was diagnosed with PS, and died at age 1 year. Morphological analysis of a muscle biopsy sample from the mother showed cytochrome c oxidase-negative ragged-red fibers-a typical pattern in patients with mtDNA deletions. Southern blot analysis using multiple restriction endonucleases and probed with multiple mtDNA fragments showed that both the mother and her infant son harbored an identical 5,355-bp single deletion in mtDNA, without flanking direct repeats. The deletion was the only abnormal species of mtDNA identified in both patients, and there was no evidence for duplications. We conclude that, although the vast majority of single large-scale deletions in mtDNA are sporadic, in rare cases, single deletions can be transmitted through the germline.