Biomedical subjects
Publications and source records attributed to J M Cooper.
The value of extirpative surgery for excessive uterine bleeding is questionable. A number of technologies have been developed that destroy the endometrial lining while preserving the uterus. This article compares and contrasts multiple modalities of global endometrial ablation technology.
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STUDY OBJECTIVE: To compare a distensible multielectrode balloon for endometrial ablation with electrosurgical ablation performed by a combined resection-coagulation technique. DESIGN: Randomized, prospective trial (Canadian Task Force classification I). Setting. Eight centers. PATIENTS: Women with menorrhagia validated with a standardized pictorial blood loss assessment chart (PBAC), without intracavitary organic uterine disease, who failed or poorly tolerated medical therapy. Intervention. Results in 122 patients treated by Vesta and 112 treated surgically, evaluable at 1 year, were compared, with success defined as monthly blood loss of less than 80 ml and avoidance of additional therapy. MEASUREMENTS AND MAIN RESULTS: Pretreatment PBAC scores for patients treated by Vesta and resection or rollerball were 535+/-612 and 445 +/- 313, respectively; at 1 year they were 18+/-37 and 28+/-60, respectively. With PBAC below 75 as the definition of success, 86.9% of Vesta-treated patients were successful compared with 83.0% treated by rollerball or resection. Total amenorrhea, defined as no visible bleeding and no use of protective products, was 31.1% and 34. 8%, respectively. None of the outcome comparisons between treatments showed statistical difference. Complications in both groups were few and minor. Most (86.6%) Vesta procedures were carried out with paracervical block with or without intravenous sedation in an office or outpatient setting, compared with 79.7% epidural or general anesthesia for rollerball or resection. CONCLUSION: The Vesta system of endometrial ablation is equally effective and safe as classic resectoscopic methods. Potential advantages include avoidance of fluid and electrolyte disturbance associated with intravasation of distending media, and ability to perform the procedure under local anesthesia in an office setting with less total operating time.
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Cytochrome c oxidase (COX) is encoded by three mitochondrial and nine nuclear genes. COX deficiency is genetically heterogeneous but current diagnostic methods cannot easily distinguish between mitochondrial and nuclear defects. We hypothesized that there may be differential expression of COX subunits depending on the underlying mutation. COX subunit expression was investigated in five patients with known mtDNA mutations. Severe and selective reduction of mtDNA-encoded COX subunits I and II was consistently observed in all these patients and was restricted to COX-deficient fibres. Immunostaining of nuclear-encoded subunits COX IV and Va was normal, whilst subunit VIc, also nuclear-encoded, was decreased. Twelve of 36 additional patients with histochemically defined COX deficiency also had this pattern of staining, suggesting that they had mtDNA defects. Clinical features in this group were heterogeneous, including infantile encephalopathy, multisystem disease, cardiomyopathy and childhood-onset isolated myopathy. The remaining patients did not have the same pattern of immunostaining. Fourteen had reduced staining of all subunits, whilst 10 had normal staining of all subunits despite reduced enzyme activity. Patients with COX deficiency secondary to mtDNA mutations have a specific pattern of subunit loss, but the majority of children with COX deficiency do not have this pattern of subunit loss and are likely to have nuclear gene defects.
PURPOSE: To compare the prevalence of hepatic arterial complications in patients who underwent hepatic arterial chemoembolization for hepatocellular carcinomas before orthotopic liver transplantation with the prevalence of hepatic arterial complications in the total population of liver transplant recipients. MATERIALS AND METHODS: Forty-seven patients underwent selective hepatic arterial chemoinfusion with mitomycin C, doxorubicin hydrochloride, and cisplatin combined with embolization. The prevalence rates for hepatic arterial complications, including pseudoaneurysm, stenosis, anastomotic disruption, and thrombosis, were tabulated and compared with results in 1,154 patients who underwent orthotopic liver transplantation but not chemoembolization. RESULTS: Of the 47 patients who had undergone preoperative hepatic arterial chemotherapy, 13% developed hepatic arterial complications within a mean of 7 days after transplantation; an 8% prevalence of hepatic arterial thrombosis was observed. Of the 1,154 patients who underwent orthotopic liver transplantation but not chemotherapy, 6% developed hepatic arterial complications; a 5% prevalence of hepatic arterial thrombosis was observed. There was no statistically significant difference in the prevalence rates for thrombosis and complications between the patients who underwent chemoembolization before orthotopic liver transplantation and those who did not. The mean interval between chemotherapy and orthotopic liver transplantation was 111 days (range, 3-428 days). CONCLUSION: Patients who undergo hepatic arterial chemotherapy are not at an increased risk of developing hepatic arterial thrombosis or other hepatic arterial complications after orthotopic liver transplantation.
Friedreich ataxia (FRDA), the most common of the inherited ataxias, is an autosomal recessive degenerative disorder, characterized clinically by onset before the age of 25 of progressive gait and limb ataxia, absence of deep tendon reflexes, extensor plantar responses, and loss of position and vibration sense in the lower limbs. FRDA is caused by a GAA triplet expansion in the first intron of the FRDA gene on chromosome 9q13 in 97% of patients. The FRDA gene encodes a widely expressed 210-aa protein, frataxin, which is located in mitochondria and is severely reduced in FRDA patients. Frataxin function is still unknown but the knockout of the yeast frataxin homologue gene (YFH1) showed a severe defect of mitochondrial respiration and loss of mtDNA associated with elevated intramitochondrial iron. Here we report in vivo evidence of impaired mitochondrial respiration in skeletal muscle of FRDA patients. Using phosphorus magnetic resonance spectroscopy we demonstrated a maximum rate of muscle mitochondrial ATP production (V(max)) below the normal range in all 12 FRDA patients and a strong negative correlation between mitochondrial V(max) and the number of GAA repeats in the smaller allele. Our results show that FRDA is a nuclear-encoded mitochondrial disorder affecting oxidative phosphorylation and give a rationale for treatments aimed to improve mitochondrial function in this condition.
Complex I is the largest of the mitochondrial respiratory chain proteins, and contains subunits encoded by both mitochondrial and nuclear genomes. Leber's hereditary optic neuropathy has been clearly linked to mutations of mitochondrial DNA complex I genes, and variable complex I functional defects have been reported. We have confirmed an approximate 60% defect in mitochondrial NADH CoQ1 reductase activity in cultured fibroblasts bearing the 3460-bp G to A mutation within the ND1 gene. However complex I-linked ATP synthesis was found to be normal in these fibroblasts. A 60% rotenone-induced decrease in complex I activity was shown to reduce ATP synthesis in normal fibroblasts, indicating that this level of complex I activity was below the threshold required to affect ATP synthesis. Although 3460 LHON mitochondria were less sensitive to rotenone inhibition, this did not explain the decreased complex I activity as the rotenone insensitive activity was not increased, nor did the inhibitor diphenyleneiodonium inhibit the NADH CoQ1 reductase activity to a greater extent. Decreased NADH cytochrome c reductase activity in cybrids homoplasmic for the 3460 LHON mtDNA mutation confirmed that the decrease in complex I activity was not specific to the assay used and was not caused by inhibitory effects of ubiquinone analogues used in the NADH CoQ1 reductase assay. These findings have important implications for our understanding of complex I dysfunction in the pathogenesis of 3460 Leber's hereditary optic neuropathy.
MitBASE is an integrated and comprehensive database of mitochondrial DNA data which collects all available information from different organisms and from intraspecie variants and mutants. Research institutions from different countries are involved, each in charge of developing, collecting and annotating data for the organisms they are specialised in. The design of the actual structure of the database and its implementation in a user-friendly format are the care of the European Bioinformatics Institute. The database can be accessed on the Web at the following address: http://www.ebi.ac. uk/htbin/Mitbase/mitbase.pl. The impact of this project is intended for both basic and applied research. The study of mitochondrial genetic diseases and mitochondrial DNA intraspecie diversity are key topics in several biotechnological fields. The database has been funded within the EU Biotechnology programme.
Human MitBASE is a database collecting human mtDNA variants. This database is part of a greater mitochondrial genome database (MitBASE) funded within the EU Biotech Program. The present paper reports the recent improvements in data structure, data quality and data quantity. As far as the database structure is concerned it is now fully designed and implemented. Based on the previously described structure some changes have been made to optimise both data input and data quality. Cross-references with other bio-databases (EMBL, OMIM, MEDLINE) have been implemented. Human MitBASE data can be queried with the MitBASE Simple Query System (http://www.ebi.ac.uk/htbin/Mitbase/mit base.pl) and with SRS at the EBI under the 'Mutation' section (http://srs.ebi.ac.uk/srs5/). At present the HumanMitBASE node contains approximately 5000 variants related to studies investigating population polymorphisms and pathologies.
This article expands the scope of the therapeutic jurisprudence enterprise and applies the concept at a collective global level. The right of self-determination, arguably the most important and certainly the most controversial part of international law, is examined through the lens of therapeutic jurisprudence. By detailing the manner in which nations move towards their goal of statehood, this article opens up dialogue about collective healing, shared memory and alternative approaches to autonomy. The article poses the question of whether groups of people can share in common delusions, forms of folie a gens.
The physiological role of huntingtin and the mechanisms by which the expanded CAG repeat in ITI5 and its polyglutamine stretch in mutant huntingtin induce Huntington's disease (HD) are unknown. Several techniques have now demonstrated abnormal metabolism in HD brain; direct measurement of respiratory chain enzyme activities has shown severe deficiency of complex II/III and a milder defect of complex IV. We confirm that these abnormalities appear to be confined to the striatum within the HD brain. Analysis of complex II/III activity in HD fibroblasts was normal, despite expression of mutant huntingtin. Although glyceraldehyde 3-phosphate dehydrogenase (a huntingtin binding protein) activity was normal in all areas studied, aconitase activity was decreased to 8% in HD caudate, 27% in putamen, and 52% in cerebral cortex, but normal in HD cerebellum and fibroblasts. We have demonstrated that although complexes II and III are those parts of the respiratory chain most vulnerable to inhibition in the presence of a nitric oxide (NO*) generator, aconitase activity was even more sensitive to inhibition. The pattern of these enzyme deficiencies and their parallel to the anatomical distribution of HD pathology support an important role for NO* and excitotoxicity in HD pathogenesis. Furthermore, based on the biochemical defects we have described, we suggest that NO* generation produces a graded response, with aconitase inhibition followed by complex II/III inhibition and the initiation of a self-amplifying cycle of free radical generation and aconitase inhibition, which results in severe ATP depletion. We propose that these events are important in determining neuronal cell death and are critical steps in the pathogenesis of HD.
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Mitochondrial DNA depletion syndrome is an autosomal inherited disease associated with grossly reduced cellular levels of mitochondrial DNA in infancy. Most patients are born after a full and uncomplicated pregnancy, are normal at birth, but develop symptoms in the early neonatal period. These observations have led to the suggestion that the patients have a defect affecting the control of mitochondrial DNA copy number after birth. Using immunocytochemical techniques, we demonstrated that the disease is already expressed in amniotic fluid cells. Detection of mitochondrial DNA depletion in these fetal cells indicates that the defect may already be expressed early in embryological development.
Microsensors have traditionally been made as one-off, hand-crafted probes. Recently, however, there has been a concerted drive to exploit the microfabrication methods developed within the semiconductor industry in order to mass produce cheap, planar microsensing arrays. Such devices might be 'electronic Petri dishes' for the direct stimulation of, and measurement from, a variety of single cells, including neurones. In addition, micromachining has been used to construct picolitre-scale analytical sensors to extend the range of single-cell analyses.
The ever-increasing value of diagnostic and operative hysteroscopy for patients with AUB serves as an appropriate, although belated, tribute to Pantaleoni who in 1869 dared to look inside a woman's uterus. Future generations of women and their physicians will be indebted to this physician-pioneer. Contemporary instrumentation permits the gynecologist to acquire quickly the basic skills necessary for routine performance of office-based hysteroscopy. With increasing experience, operative hysteroscopic techniques, including resection of polyps, myomata, and endometrial ablation, can be easily mastered.