Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report three members of a family, who exhibited a phenotype similar to 'myoclonus epilepsy with ragged-red fibers' but had a genotype usually associated with 'mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes'. The patients, a 48-year-old female, and her two sons, aged 21 and 19 respectively, presented with photo-reactive syncopal episodes, disturbances of gait and writing, dysarthria and finger tremor since the 3rd and 2nd decade of life, respectively, that were accompanied also by numbness and weakness of the extremities. Subsequently, cerebellar ataxia and myoclonus were also noted. Electromyography revealed both myogenic and neurogenic muscular changes, and nerve conduction studies demonstrated a sensory-motor neuropathy. Biopsy showed ragged-red fibers with strongly stained SDH-positive vessels in skeletal muscles, and a marked loss of myelinated fibers of the sural nerves. Mitochondrial (mt) DNA analyses of peripheral blood, muscles and nerves revealed that all members had a heteroplasmic np3271 (T-C) point mutation in the mitochondrial tRNA-Leu gene (UUR). This family is unique, in that all patients presented with a myoclonus epilepsy with ragged-red fibers-like phenotype and had a distinctive peripheral neuropathy, while the detected mtDNA 327l (T-C) mutation has been reported to date only in rare cases of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes
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PMID:A mitochondrial encephalo-myo-neuropathy with a nucleotide position 3271 (T-C) point mutation in the mitochondrial DNA. 1140 19

This gene transfer experiment is the first Parkinson's Disease (PD) protocol to be submitted to the Recombinant DNA Advisory Committee. The principal investigators have uniquely focused their careers on both pre-clinical work on gene transfer in the brain and clinical expertise in management and surgical treatment of patients with PD. They have extensively used rodent models of PD for proof-of-principle experiments on the utility of different vector systems. PD is an excellent target for gene therapy, because it is a complex acquired disease of unknown etiology (apart from some rare familial cases) yet it is characterized by a specific neuroanatomical pathology, the degeneration of dopamine neurons of the substantia nigra (SN) with loss of dopamine input to the striatum. This pathology results in focal changes in the function of several deep brain nuclei, which have been well-characterized in humans and animal models and which account for many of the motor symptoms of PD. Our original approaches, largely to validate in vivo gene transfer in the brain, were designed to facilitate dopamine transmission in the striatum using an AAV vector expressing dopamine-synthetic enzymes. Although these confirmed the safety and potential efficacy of AAV, complex patient responses to dopamine augmenting medication as well as poor results and complications of human transplant studies suggested that this would be a difficult and potentially dangerous clinical strategy using current approaches. Subsequently, we and others investigated the use of growth factors, including GDNF. These showed some encouraging effects on dopamine neuron survival and regeneration in both rodent and primate models; however, uncertain consequences of long-term growth factor expression and question regarding timing of therapy in the disease course must be resolved before any clinical study can be contemplated. We now propose to infuse into the subthalamic nucleus (STN) recombinant AAV vectors expressing the two isoforms of the enzyme glutamic acid decarboxylase (GAD-65 and GAD-67), which synthesizes the major inhibitory neurotransmitter in the brain, GABA. The STN is a very small nucleus (140 cubic mm or 0.02% of the total brain volume, consisting of approximately 300,000 neurons) which is disinhibited in PD, leading to pathological excitation of its targets, the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNpr). Increased GPi/SNpr outflow is believed responsible for many of the cardinal symptoms of PD, i.e., tremor, rigidity, bradykinesia, and gait disturbance. A large amount of data based on lesioning, electrical stimulation, and local drug infusion studies with GABA-agonists in human PD patients have reinforced this circuit model of PD and the central role of the STN. Moreover, the closest conventional surgical intervention to our proposal, deep brain stimulation (DBS) of the STN, has shown remarkable efficacy in even late stage PD, unlike the early failures associated with recombinant GDNF infusion or cell transplantation approaches in PD. We believe that our gene transfer strategy will not only palliate symptoms by inhibiting STN activity, as with DBS, but we also have evidence that the vector converts excitatory STN projections to inhibitory projections. This additional dampening of outflow GPi/SNpr outflow may provide an additional advantage over DBS. Moreover, of perhaps the greatest interest, our preclinical data suggests that this strategy may also be neuroprotective, so this therapy may slow the degeneration of dopaminergic neurons. We will use both GAD isoforms since both are typically expressed in inhibitory neurons in the brain, and our data suggest that the combination of both isoforms is likely to be most beneficial. Our preclinical data includes three model systems: (1) old, chronically lesioned parkinsonian rats in which intraSTN GAD gene transfer results not only in improvement in both drug-induced asymmetrical behavior (apomorphine symmetrical rotations), but also in spontaneous behaviors. In our second model, GAD gene transfer precedes the generation of a dopamine lesion. Here GAD gene transfer showed remarkable neuroprotection. Finally, we carried out a study where GAD-65 and GAD-67 were used separately in monkeys that were resistant to MPTP lesioning and hence showed minimal symptomatology. Nevertheless GAD gene transfer showed no adverse effects and small improvements in both Parkinson rating scales and activity measures were obtained. In the proposed clinical trial, all patients will have met criteria for and will have given consent for STN DBS elective surgery. Twenty patients will all receive DBS electrodes, but in addition they will be randomized into two groups, to receive either a solution containing rAAV-GAD, or a solution which consists just of the vector vehicle, physiological saline. Patients, care providers, and physicians will be blind as to which solution any one patient receives. All patients, regardless of group, will agree to not have the DBS activated until the completion and unblinding of the study. Patients will be assessed with a core clinical assessment program modeled on the CAPSIT, and in addition will also undergo a preop and several postop PET scans. At the conclusion of the study, if any patient with sufficient symptomatic improvement will be offered DBS removal if they so desire. Any patients with no benefit will simply have their stimulators activated, which would normally be appropriate therapy for them and which requires no additional operations. If any unforeseen symptoms occur from STN production of GABA, this might be controlled by blocking STN GABA release with DBS, or STN lesioning could be performed using the DBS electrode. Again, this treatment would not subject the patient to additional invasive brain surgery. The trial described here reflects an evolution in our thinking about the best strategy to make a positive impact in Parkinson Disease by minimizing risk and maximizing potential benefit. To our knowledge, this proposal represents the first truly blinded, completely controlled gene or cell therapy study in the brain, which still provides the patient with the same surgical procedure which they would normally receive and should not subject the patient to additional surgical procedures regardless of the success or failure of the study. This study first and foremost aims to maximally serve the safety interests of the individual patient while simultaneously serving the public interest in rigorously determining in a scientific fashion if gene therapy can be effective to any degree in treating Parkinson's disease.
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PMID:Subthalamic GAD gene transfer in Parkinson disease patients who are candidates for deep brain stimulation. 1152 46

The hamster black tremor (bt) mutation induces a black coat color and a defective myelination in the central nervous system (CNS) that manifests as a tremor. On the other hand, loss-of-function mutations of the Attractin (Atrn) gene, such as Atrnmg, Atrnmg-L, and Atrnmg-3J in mice, and Atrnzi in rats, induce both darkening of coat color and hypomyelination and vacuolation in the CNS. The close resemblance of the mutant phenotypes led us to postulate that the bt/bt hamster also might harbor a mutation in Atrn. Here, we cloned the hamster Atrn cDNA and identified bt as a loss-of-function mutation of Atrn. While the human and rat Atrn genes encode both membrane- and secreted-type proteins, the hamster Atrn gene encoded only membrane-type protein with 1,427 amino acids, as in the case of the mouse. Hamster Attractin protein had 93.6%, 96.8%, and 96.8% identities with human, rat, and mouse membrane-type Attractin. In the brain of the bt/bt hamster, aberrant transcripts with more than three size species were observed, and the most predominant transcript encoded the truncated Attractin without transmembrane domain. In the Atrn gene of bt/bt hamster, an approximately 10-kb DNA fragment, which had 557-bp direct repeats in both ends and was flanked by the identical 6-bp target duplication sequences, was inserted into exon 24. In addition, the insertion was cosegregated with neurodegeneration in the CNS of 50 intercross progeny. These results indicated that the hamster bt mutation was the approximately 10-kb retrotransposon-like insertion into the Atrn gene, which resulted in aberrant transcripts. The bt/bt hamster will provide a useful tool for further understanding of the pleiotropic functions of Attractin.
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PMID:Insertional mutation of the Attractin gene in the black tremor hamster. 1177 67

Tuberculosis remains a leading killer worldwide, and new approaches for its treatment and prevention are urgently needed. This effort will benefit greatly from a better understanding of gene regulation in Mycobacterium tuberculosis, particularly with respect to this pathogen's response to its host environment. We examined the behavior of two promoters from the divergently transcribed M. tuberculosis genes acr/hspX/Rv2031c (alpha-crystallin homolog) and Rv2032/acg (acr-coregulated gene) by using a promoter-GFP fusion assay in Mycobacterium bovis BCG. We found that Rv2032 is a novel macrophage-induced gene whose expression is coregulated with that of acr. Relative levels of intracellular induction for both promoters were significantly affected by shallow standing versus shaking bacterial culture conditions prior to macrophage infection, and both promoters were strongly induced under low oxygen conditions. Deletion analyses showed that DNA sequences within a 43-bp region were required for expression of these promoters under all conditions. Multiple sequence alignment and database searches performed with PROBE indicated that Rv2032 is one of eight M. tuberculosis genes of previously unknown function that belong to an unusual superfamily of classical nitroreductases, which may have a role for bacteria within the host environment. These findings show that mycobacterial culture conditions can greatly influence the results and interpretation of subsequent gene regulation experiments. We propose that these differences might be exploited for dissection of the regulatory factors that affect mycobacterial gene expression within the host.
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PMID:Identification of a Mycobacterium tuberculosis putative classical nitroreductase gene whose expression is coregulated with that of the acr aene within macrophages, in standing versus shaking cultures, and under low oxygen conditions. 1185 40

CAG repeat expansions with loss of CAT interruptions in the coding region of the ataxin-1 gene are associated with spinocerebellar ataxia type 1 (SCA1). For molecular genetic diagnosis it is necessary to define the limits of normal and pathological size ranges. In most studies, normal alleles as measured by PCR range from 6-39 units with interruptions of 1-3 CAT trinucleotides that are thought to be involved in the stability of the trinucleotide stretch during DNA replication. Expanded alleles have been reported to carry 39-81 CAG trinucleotides without stabilising CAT interruptions. To evaluate the limits between normal and disease size ranges we analysed the repeat length and composition of the SCA1 gene in 15 individuals with alleles ranging from 36 and 41 triplets for genotype-phenotype correlation studies. We found the 39 trinucleotide-allele to be either interrupted by CAT repeats or formed by a pure CAG stretch. The clinical features of individuals carrying 39 uninterrupted CAG repeats did not differ from the SCA1 phenotype in general with dysphagia, pale discs, pyramidal signs and cerebellar tremor being more frequent as compared to other SCA genotypes. In contrast, the interrupted 39 trinucleotide-allele is not correlated with the SCA1 phenotype.
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PMID:Spinocerebellar ataxia type 1 (SCA1): phenotype-genotype correlation studies in intermediate alleles. 1197 25

Laboratory evolution in Escherichia coli has revealed that fitness typically increases in experimental populations. These changes are sometimes associated with changes in insertion sequence positions, some of which may themselves cause advantageous phenotypes. We have a novel and general method for identifying genes in Escherichia coli, whose knockout by mobile DNA insertions is beneficial in experimental evolution. Insertion sites in favored clones can be identified by reference to genomic information. We have implemented the method using modified Tn10 transposons bearing kanamycin and chloramphenicol resistance cassettes. Results are consistent across replicated experiments, demonstrating that the insertions are themselves creating selective advantages, rather than hitch-hiking with favorable base substitutions. The successful clones have subsequently been confirmed to have a fitness advantage relative to the progenitor strain. In experiments in shaking culture, we find that advantageous insertions usually fall in operons required in the pathways creating flagella. The method allows a rapid genome-wide screening for advantageous insertions in arbitrary environmental conditions. It allows investigation of the extent to which transient mutations generating environment-dependent selective advantages may help to explain the persistence of mobile DNAs in primarily clonal organisms, such as E. coli.
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PMID:A simple method for genome-wide screening for advantageous insertions of mobile DNAs in Escherichia coli. 1201 26

A differential molecular screening procedure was developed to obtain DNA clones enriched for verrucosidin-related genes that could be used as DNA probes to detect verrucosidin-producing Penicillium polonicum. Permissive and nonpermissive conditions for verrucosidin production were selected to obtain differentiated poly (A)+ RNA for the cloning strategy. P. polonicum yielded the highest amount of verrucosidin when cultured in malt extract broth at 25 degrees C without shaking. These conditions were selected as verrucosidin permissive conditions. When shaking was applied to the verrucosidin permissive conditions, verrucosidin was not detected. Approximately 5000 transformants were obtained for the library of DNA fragments from verrucosidin-producing P. polonicum and hybridized with cDNA probes obtained from poly (A)+ RNA of permissive and nonpermissive conditions. A total of 120 clones hybridized only with the permissive cDNA probes. From these, eight representative DNA inserts selected on the basis of size and labelled with fluorescein-dUTP were assayed as DNA probes in the second differential screening by Northern hybridization. Probe SVr1 gave a strong hybridization signal selectively with poly (A)+ RNAs from high verrucosidin production. When this probe was assayed by dot blot hybridization with DNA of different moulds species, hybridization was detected only with DNA from the verrucosidin-producing strain. The strategy used in this work has proved to be useful to detect unknown genes related to mycotoxins. In addition, the DNA probe obtained should be considered for the detection of verrucosidin-producing moulds.
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PMID:Molecular cloning of verrucosidin-producing Penicillium polonicum genes by differential screening to obtain a DNA probe. 1203 78

The Kearns-Sayre syndrome (characterized by onset before 20, chronic ophthalmoplegia, pigmentary retinal degeneration and at least 1 of the following symptoms: ataxia, heart block and high protein content in the cerebrospinal fluid) is a severe variant of chronic progressive external ophthalmoplegia (CPEO) with frequent re-arrangements of the mitochondrial DNA (mtDNA). The aim of this paper is to report a sporadic paediatric case of Kearns-Sayre syndrome with mtDNA heteroplasmic deletion, absence of cytochrome c oxidase in many muscle fibers, autoimmune thyroiditis followed by depressive phobic disturbances, slowing EEG, hyperreflexia, tremor and visual hallucinations, in which the diagnosis of possible encephalopathy associated with autoimmune thyroid disease (Hashimoto encephalopathy) was made. We speculated that in this patient, predisposed by mitochondrial deletion, anti-thyroid antibodies may have interfered with mitochondrial cerebral function, causing Hashimoto encephalopathy and facilitating ophthalmoplegia. It seems important to study anti-thyroid antibodies in every case of Kearns-Sayre syndrome, specially if ophthalmoplegia is recent, even in order to the therapy.
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PMID:A case of Kearns-Sayre syndrome with autoimmune thyroiditis and possible Hashimoto encephalopathy. 1209 44

Shaken baby syndrome, a rotational acceleration injury, is most common between 3 and 6 months of age and causes death in about 10 to 40% of cases and permanent neurological abnormalities in survivors. We developed a mouse model of shaken baby syndrome to investigate the pathophysiological mechanisms underlying the brain damage. Eight-day-old mouse pups were shaken for 15 seconds on a rotating shaker. Animals were sacrificed at different ages after shaking and brains were processed for histology. In 31-day-old pups, mortality was 27%, and 75% of survivors had focal brain lesions consisting of hemorrhagic or cystic lesions of the periventricular white matter, corpus callosum, and brainstem and cerebellar white matter. Hemorrhagic lesions were evident from postnatal day 13, and cysts developed gradually between days 15 and 31. All shaken animals, with or without focal lesions, had thinning of the hemispheric white matter, which was significant on day 31 but not earlier. Fragmented DNA labeling revealed a significant increase in cell death in the periventricular white matter, on days 9 and 13. White matter damage was reduced by pre-treatment with the NMDA receptor antagonist MK-801. This study showed that shaking immature mice produced white matter injury mimicking several aspects of human shaken baby syndrome and provided evidence that excess release of glutamate plays a role in the pathophysiology of the lesions.
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PMID:Delayed white matter injury in a murine model of shaken baby syndrome. 1214

Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal-dominant neurodegenerative disorder characterized by variable combination of clinical manifestations including ataxia, myoclonus, seizures, dementia, and choreic movements. Head tremor has been rarely reported. We report a 66-year-old-woman with genetically determined DRPLA who presented with head tremor. A "no-no" type head tremor was the initial and the most prominent symptom, and mild cerebellar signs and choreic movements were also observed later. Neither hand tremor nor dystonia was noted. The patient did not show dementia, myoclonus, or seizures. Surface electromyogram (EMG) revealed 3.5-4 Hz rhythmic EMG bursts in both sternocleidomastoid muscles. DNA analysis disclosed expanded trinucleotide repeats (n = 54) in the DRPLA gene. We suggest that isolated head tremor can be a clinical manifestation of DRPLA.
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PMID:Head tremor in dentatorubral-pallidoluysian atrophy. 1237 28


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