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71.
Identification of the gene encoding the human mitochondrial RNA polymerase (h-mtRPOL) by cyberscreening of the Expressed Sequence Tags database 总被引:12,自引:3,他引:9
Tiranti V; Savoia A; Forti F; D'Apolito MF; Centra M; Rocchi M; Zeviani M 《Human molecular genetics》1997,6(4):615-625
A gene cloning strategy based on the screening of the Expressed Sequence
Tags database (dbEST) using sequences of mitochondrial housekeeping
proteins of yeast was employed to identify the cDNA encoding the precursor
of the human mitochondrial RNA polymerase (h- mtRPOL). The 3831 bp h-mtRPOL
cDNA is located on chromosome 19p13.3 and encodes a protein of 1230 amino
acid residues. The protein sequence shows significant homologies with
sequences corresponding to mitochondrial RNA polymerases from lower
eukaryotes, and to RNA polymerases from several bacteriophages. The
mitochondrial RNA polymerase carries out the central activity of
mitochondrial gene expression and, by providing the RNA primers for
replication- initiation, is also implicated in the maintenance and
propagation of the mitochondrial genome. Genes involved in the control of
mtDNA replication and gene expression are attractive candidates for human
disorders due to abnormalities of nucleo-mitochondrial intergenomic
signalling. The availability of the h-mtRPOL cDNA will allow us to test its
role in mitochondrial pathology. In addition, we propose the
'cyberscreening' of dbEST, based on yeast/human cross-species comparison,
as a powerful, simple, rapid and inexpensive method, that may accelerate
several-fold the molecular dissection of the human mitochondrial proteome.
相似文献
72.
M-LA Schuttelaar MF Jonkman 《Journal of the European Academy of Dermatology and Venereology》2003,17(1):91-93
We report a patient with Churg-Strauss syndrome (CSS) with asthma, eosinophilia, nasal polyposis and ANCA-associated multisystem vasculitis, who's skin eruption started with erythematous urticarial-plaques followed by haemorrhagic bullae. Histology of the plaques revealed 'flame figures' in the dermis with no granulomatous or vasculitic process, consistent with the diagnosis of eosinophilic cellulitis or Wells' syndrome. The association of CSS and Wells' syndrome observed in this patient may have a common pathogenesis. CSS may induce Wells' syndrome by an unknown factor. 相似文献
73.
74.
Acute otomastoiditis and its complications: role of CT 总被引:2,自引:0,他引:2
Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess. 相似文献
75.
76.
77.
Fc-independent cross-linking of a novel platelet membrane protein by a monoclonal antibody causes platelet activation 总被引:1,自引:0,他引:1
A monoclonal antiplatelet antibody (MA-13G8E1) is described that dose- dependently induces platelet aggregation and serotonin release in an Fc- independent fashion. Whereas platelets were equally aggregated by F(ab')2 fragments of this monoclonal antibody (MoAb), its Fab fragments, on the other hand, were inactive, indicating that divalent interaction is an essential requirement to induce platelet activation by MA-13G8E1. In addition, we could show that platelet epitope cross- linking by MA-13G8E1 occurred on the same platelet. MA-13G8E1 stimulated platelet phospholipase C (PLC) and induced activation of protein kinase C (PKC), both of which were almost unaffected by aspirin pretreatment. Furthermore, PLC activation appeared to be a direct antibody-mediated effect, since intracellular Ca2+ rises were not inhibited by EGTA, cytochalasin B, or aggregation-blocking MA-16N7C2 (antiglycoprotein [anti-GP]IIb/IIa). The MA-13G8E1 antigen is constitutively expressed on resting platelets of different species (7,100 +/- 800 molecules per human platelet), but not on other cell types tested. Both immunoprecipitation and affinity isolation by MA- 13G8E1 showed two low-molecular weight proteins (45 and 36 kD), having slightly acidic isoelectric pH levels (4.5 to 5.5) and forming multimolecular complexes. In conclusion, we found an MoAb that is able to induce platelet activation in an Fc-independent fashion. The mechanism involves cross-linking of a hitherto undescribed platelet membrane protein, leading to PLC and PKC stimulation. 相似文献
78.
Carpino A; Siciliano L; Petroni MF; De Stefano C; Aquila S; Ando S; Petrone MF$corrected to Petroni MF 《Human reproduction (Oxford, England)》1998,13(1):111-114
Total seminal zinc concentration, seminal zinc fraction bound to high
molecular weight proteins (HMW-Zn%) and zinc content in spermatozoa were
assayed in the ejaculates of 90 asthenozoospermic patients subdivided into
two study groups: normoasthenozoospermics (group I: n = 50) and
oligoasthenozoospermics (group II: n = 40). The zinc concentrations of
patients were compared with those of a control group of donors showing
normal semen parameters. All samples were also investigated for their sperm
membrane functional integrity by the hypo- osmotic swelling test (HOS). The
results showed normal total zinc concentrations but very low HMW-Zn% values
(P < 0.001) in seminal plasma of the two groups of asthenozoospermic
patients compared to the controls. Furthermore higher zinc amounts (P <
0.001) were measured in spermatozoa of oligoasthenozoospermic patients
compared to group I and to the control group. Oligoasthenozoospermics also
displayed a lower HOS score (P < 0.001) compared to the other two
groups. These data suggest that the increased unbound seminal zinc could
contribute to the decrease of sperm motility in normoasthenozoospermic and
oligoasthenozoospermic patients. A further impairment in sperm motility
could occur in the oligoasthenozoospermic patients where the increase of
seminal free zinc was followed by a major zinc uptake by spermatozoa. The
higher intrasperm zinc content in these patients could be a reflection of
their low sperm membrane functionality.
相似文献
79.
80.
Magnuson JE; Brown ML; Hauser MF; Berquist TH; Fitzgerald RH Jr; Klee GG 《Radiology》1988,168(1):235-239
When infection of prosthetic orthopedic implants is suspected, optimal management requires accurate confirmation or exclusion of infection. The authors retrospectively studied 98 patients with possible infection who underwent scanning with indium-111-labeled white blood cells (WBCs) and subsequently underwent surgery within 14 days. At surgery, 50 patients had infections, as determined by means of culture or histologic results. The diagnostic accuracy of In-111 scanning was compared with that of plain radiography, arthrography, three-phase bone scanning, and various clinical and laboratory findings classically associated with infection. Positive findings on In-111 WBC scans and elevated erythrocyte sedimentation rates were found to be the most predictive variables in the diagnosis of septic prostheses (P less than or equal to .001 and P less than or equal to .002, respectively). Likelihood ratio analysis more clearly demonstrated the superiority of In-111 WBC scanning, with positive and negative scans yielding likelihood ratios of 5.0 and 0.16, respectively. 相似文献