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At least 523 records · Page 29Linked to original sources
PubMed1976

Studies on hemoglobin variants in Korean cattle.

814 hemoglobin samples from Korean cattle were investigated by starch gel electrophoresis for the detection of hemoglobin variants. A new variant of cattle hemoglobin, called Hb, H, was recognized. It has a slower rate of migration than Hb A. Hemoglobin types from 814 Korean cattle were as follows: 652 of Hb AA type (80.1%), 133 of Hb AB (16.4%), 12 of Hb AC (1.5%), 9 of Hb BB (1.1%), 2 of Hb BC (0.2%), 4 of Hb AH (O.5%), 1 of Hb CH (0.1%), 1 of Hb HH (O.1%). These figures correspond to the frequencies: HbA = 0.893, HbB = 0.093, HbC = 0.009, HbH = 0.004.

Animals↗
PubMed1988

Homozygosity for the transthyretin-met30-gene in two Swedish sibs with familial amyloidotic polyneuropathy.

Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant inherited disorder. Recent biochemical studies have revealed that amyloid protein in FAP of Japanese, Swedish and Portuguese origin mainly consists of a variant transthyretin (TTR) (formerly called prealbumin) with one amino acid substitution of methionine for valine at position 30. In a 56-year-old man with typical polyneuropathy, gastrointestinal problems and vitreous amyloid, we diagnosed homozygosity for the TTR-met30-gene using RFLP analysis. In a family study, a sister presented the same homozygous RFLP pattern; however, in a careful clinical investigation we were not able to demonstrate any of the typical symptoms of FAP, nor could we demonstrate amyloid deposits in a biopsy skin specimen. This is the first report of homozygosity for the TTR-met30-gene, and it shows that the mutation of the protein involved in amyloid formation may be necessary but is clearly not sufficient for the clinical symptoms.

Adult↗
PubMed1991

Transcriptional analysis, translational analysis, and sequence of the kilA-tellurite resistance region of plasmid RK2Ter.

The tellurite resistance (Ter) determinant of the IncP alpha plasmid RK2Ter, a variant of RK2 (also called RP4), is located between the kilA and korA genes involved in plasmid replication control. Transcriptional and translational fusions were constructed between the gene for beta-galactosidase and the kilA and Ter genes by using the transpositional phage mini-Mu. These fusions indicated that the Ter genes are transcribed in the same direction as kilA and that transcription and translation of the cloned kilA gene are occurring and may not be lethal to the bacterial cell even in the absence of korA. The nucleotide sequence of this region was determined, and three open reading frames (ORFs) were identified. The first ORF codes for KilA, a 28-kDa hydrophilic protein. The second ORF, telA, codes for a hydrophilic protein of 42 kDa. The third ORF, telB, codes for a hydrophobic protein of 32 kDa. This protein appears to be located in the inner membrane of the bacterial cell, since fusions of TelB to alkaline phosphatase were obtained by using TnphoA. All three proteins were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after overproduction using the T7 RNA polymerase/promoter system. The same three proteins were produced when Tes and Ter derivatives of RP4 were expressed in an in vitro transcription-translation system. A single Ser-to-Cys missense mutation in telB was found to be responsible for mutation of RK2 to Ter.

Alkaline Phosphatase↗
PubMed2000

Dimers of pi protein bind the A+T-rich region of the R6K gamma origin near the leading-strand synthesis start sites: regulatory implications.

The replication of gamma origin, a minimal replicon derived from plasmid R6K, is controlled by the Rep protein pi. At low intracellular concentrations, pi activates the gamma origin, while it inhibits replication at elevated concentrations. Additionally, pi acts as a transcription factor (auto)repressing its own synthesis. These varied regulatory functions depend on pi binding to reiterated DNA sequences bearing a TGAGNG motif. However, pi also binds to a "non-iteron" site (i.e., not TGAGNG) that resides in the A+T-rich region adjacent to the iterons. This positioning places the non-iteron site near the start sites for leading-strand synthesis that also occur in the A+T-rich region of gamma origin. We have hypothesized that origin activation (at low pi levels) would require the binding of pi monomers to iterons, while the binding of pi dimers to the non-iteron site (at high pi levels) would be required to inhibit priming. Although monomers as well as dimers can bind to an iteron, we demonstrate that only dimers bind to the non-iteron site. Two additional pieces of data support the hypothesis of negative replication control by pi binding to the non-iteron site. First, pi binds to the non-iteron site about eight times less well than it binds to a single iteron. Second, hyperactive variants of pi protein (called copy-up) either do not bind to the non-iteron site or bind to it less well than wild-type pi. We propose a replication control mechanism whereby pi would directly inhibit primer formation.

Adenine↗
PubMed2003

Framing the future of antifungals in atopic dermatitis.

Atopic dermatitis (AD) is a frequent chronic inflammatory skin disease. Some fungal colonization or infection of the skin may exacerbate AD severity, particularly the so-called head and neck variant. In addition, excessive intestinal colonization by Candida albicans may represent an additional triggering factor. Hence, there is a rationale to use antifungals in selected AD patients. Early trials with topical ketoconazole in head and neck AD showed a decrease in Malassezia colonization, but no significant improvement was observed in the clinical severity. In contrast, clinical improvement and decreased serum IgE were obtained in patients with positive Malassezia radioallergosorbent tests (RASTs) who were treated by oral ketoconazole. Some preliminary data suggested that oral itraconazole treatment in AD patients reduced the need for topical corticosteroids, provided clinical improvement particularly in head and neck AD, reduced the cutaneous and intestinal fungal colonization that may trigger AD, reduced the percentage of positive Malassezia cultures and demonstrated a decrease in C. albicans and Malassezia RAST values. Furthermore, beside its antifungal action, itraconazole in part relieves pruritus and inflammation. In conclusion, oral itraconazole treatment can alleviate AD severity in selected patients. Fluconazole is also effective. Further research is warranted to identify whether the load in skin surface fungal agents, the fungal RAST values and specific prick testing should be assessed in order to optimize the antifungal management in AD patients.

Antifungal Agents↗
PubMedDate not supplied

Thoracic meningocele, meningomyelocele or myelocystocele? Diagnostic difficulties, consequent implications and treatment.

Spina bifida cystica is a closing disorder of the neural tube which infrequently occurs in the thoracic region. A rare lesion called myelocystocele is a variant of spina bifida cystica and is associated with syringomyelia, Chiari type 2 malformation and hydrocephalus. Usually the patient has no neurological deficit, but future deterioration can occur due to posterior tethering of the spinal cord by adhesions. The prenatal diagnosis by ultrasound study can be misleading and in order to attain the correct diagnosis, especially if abortion is considered, a prenatal MRI scan should be done before the parents are counselled, and should be repeated prior to operative treatment. Surgical correction of myelocystocele is not only for cosmetic reasons, but also to untether the spinal cord prophylactically to prevent future neurological deterioration. In this case report, we present a child born with a thoracic myelocystocele, the diagnostic difficulties, consequent implications and surgical treatment.

Adult↗
PubMed2004

Xeroderma pigmentosum: from symptoms and genetics to gene-based skin therapy.

Xeroderma pigmentosum (XP) is a rare, recessively inherited genodermatosis prone to ultraviolet (UV)-induced skin neoplasms from keratinocyte origin, i.e. basal and squamous cell carcinoma. Cells from classic XP patients fail to properly eliminate UV-induced DNA lesions by the nucleotide excision repair (NER) mechanism. A variant form of XP, called XP-V suffers from faulty translesion synthesis. We review here recent data on XP gene products whose alterations affect NER and result in one of the 7 complementation groups of XP. Encouraging results of retrovirus-based genetic correction of XP keratinocytes are summarized and support realistic prospects of gene therapy for the XP-C complementation group.

DNA Damage↗
PubMed2005

Human endogenous retroviruses in the primate lineage and their influence on host genomes.

Primates emerged about 60 million years ago. Since that time various primate-targeting retroviruses have integrated in the germ line of primate species, and some drifted to fixation. After germ line fixation, continued activity of proviruses resulted in intragenomic spread of so-called endogenous retroviruses (ERVs). Variant ERVs emerged, amplified in the genome and profoundly altered genome structures and potentially functionality. Importantly, ERVs are genome modifiers of exogenous origin. The human genome contains about 8% of sequences of retroviral origin. The human ERVs (HERVs) comprise many distinct families that amplified to copy numbers of up to several thousand. We review here the evolution of several well-characterized HERV families in the human lineage since initial germ line fixation. It is apparent that endogenous retroviruses profoundly affected the genomes of species in the evolutionary lineage leading to Homo sapiens.

Animals↗
PubMed1993

An alternative Pit-1 RNA splicing product reveals modular binding and nonmodular transcriptional activities of the POU-specific domain.

We have identified a form of the pituitary-specific POU protein Pit-1 that results from deletion of the POU-specific (POUs) domain by alternative RNA splicing. This natural variant of Pit-1 (called delta 4Pit-1) has revealed several aspects of the function of the POUs domain. The delta 4Pit-1 protein was characterized using a delta 4Pit-1-specific antiserum. Further, selection assays of random oligonucleotide pools identified binding site preferences for both wild type and delta 4Pit-1. Methylation interference, copper phenanthrolene, and missing contact analyses were used to compare the binding characteristics of the two forms of Pit-1 on a selected site. DNA binding affinity assays on several DNA elements revealed that the POUs domain contains a modular DNA binding activity affecting the DNA binding affinity of the entire POU domain on some, but not on other, DNA sites. Functional analysis on such DNA elements has revealed that the POUs domain is an essential, but nonmodular, component of the Pit-1 trans-activation domain dependent on its natural context within the Pit-1 protein.

Amino Acid Sequence↗
PubMed1992

An unusual variant of Capgras syndrome.

In a 40-yr.-old man a variant of Capgras syndrome called reverse subjective doubles is described. The unusual feature of the case was the presence of a delusion that the patient had been transformed into someone else.

Adult↗
PubMed2000

Effects of aging on efficiency of task switching in a variant of the trail making test.

The Trail Making Test (TMT; R. M. Reitan, 1958, 1992) is extensively used in research in neuropsychology and in aging, in part because it has been postulated to reflect executive processes, such as planning and switching. However, neurocognitive and individual-difference-based analyses of this test are complicated because of different spatial arrangements of targets, the use of letters only in Version B, and potential order effects when Version A is administered prior to Version B. The present article examines a variant of a TMT (called the Connections Test) that attempts to remedy these deficiencies. A structural equation model suggested that there were no direct effects of age on either the nonalternating or alternating versions of the Connections Test (analogous to TMT Versions A and B, respectively); rather, all age-related effects were mediated through effects on perceptual speed. Moreover, although the nonalternating and alternating versions were strongly related to one another, only the latter had significant independent relations with measures of higher order cognition.

Adolescent↗
PubMed1975

Giant-cell tumor of bone. A demographic, clinical, and histopathological study of all cases recorded in the Swedish Cancer Registry for the years 1958 through 1968.

All seventy-five cases recorded as giant-cell tumor of bone in the Swedish Cancer Registry for the years 1958 through 1968 were analyzed. At reexamination, fifty-three cases constituted genuine giant-cell tumor of bone and twenty cases were so-called "giant-cell variants". The genuine giant-cell tumors showed a significantly higher incidence in the urban than in the rural population. The recurrence rate was 42 per cent. Patients under the age of twenty-five rarely had recurrences. A high recurrence rate was found among patients with tumors located in the distal end of the femur and the proximal end of the tibia. Tumors penetrating through the bone cortex were more aggressive than those located entirely within bone, regardless of tumor size and presence or absence of spontaneous fracture. A malignant course was found in 11.3 per cent of cases, predominantly in patients with tumors in the femur. Histopathological grading was of no prognostic value. Primary en bloc resection with or without prosthetic replacement is recommended in patients over the age of twenty-five.

Adolescent↗
PubMedDate not supplied

[Bilateral pheochromocytoma associated with duodeno-jejunal GIST in patient with von Recklinghausen disease: report of a clinical case].

The authors present the case of a 60-year-old male patient suffering from von Recklinghausen's disease (neurofibromatosis type I, NF1) with bilateral pheochromocytoma and occasional intraoperative reports of duodenojejunal GIST (GastroIntestinal Stromal Tumour). Through a review of the literature the authors analyze the frequency and the features of bilateral pheochromocytoma and its rare histological variant, the so-called composite pheochromocytoma, characterized by the combination of pheochromocytoma and ganglioneuroma or ganglioneuro-blastoma. Bilaterality of pheochromocytoma is more frequent in patients with familiarity for pheochromocytoma without NF1. Composite pheochromocytoma accounts for about 3% of total pheochromocytomas. In addition, the authors summarize the present knowledge about gastrointestinal stromal tumours and investigate the possible association between them and NF1 or pheochromocytoma, concluding that any such association is purely casual, while confirming the well known, genetically determined association between NF1 and pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed2002

[Polymorphism in allergens].

Allergens are antigens that elicit an IgE-mediated immune response; they originate from diverse sources such as pollens, mites, molds, mammal exudates, insects and food. Allergenic molecules can contain several antigenic determinants, termed epitopes. Allergenic proteins have been discovered with polymorphisms, i.e., a mixture of similar molecules with minor variations in their amino acid sequences. These are called isoallergens or allergenic variants depending on the degree of similarity. Polymorphism may be defined by the presence of several alleles of the same gene or as families of related genes. Polymorphisms can have an important effect on the epitopes recognized by T lymphocytes, monoclonal antibodies and IgE of allergic patients. Individual polymorphisms can affect the basal level of allergenicity as well as the cross-reactivity with other allergens. The use of isoforms with low or total absence of IgE binding capacity but with high capacity to stimulate T cell response has been suggested as an alternative to the conventional immunotherapy for allergic diseases. Standardization of allergenic compounds can be affected by the differing proportions of isoforms in allergenic sources from different regions.

Allergens↗
PubMed2002

[Gene diagnosis of Alzheimer's disease and Parkinson's disease].

Alzheimer's disease(AD) is the most common form of neurodegenerative diseases that causes intellectual dysfunction. AD is a genetically heterogenous disorder. Over 100 mutations have been identified in three causative genes, i.e. amyloid protein precursor(APP), presenilin 1(PS1) and presenilin 2(PS2) genes, for early-onset autosomal dominant familial AD(FAD). Apolipoprotein E(APOE) gene has been identified as susceptibility gene for late-onset FAD. The missense mutations in the causative genes lead to abnormal APP processing with overproduction of total A beta protein or A beta 42(43) isoform. The epsilon 4 allele of APOE gene is a genetic risk factor for sporadic AD as well as FAD. Parkinson's disease(PD) is another common form of neurodegenerative disease that causes movement dysfunction. Three genes, i.e. alpha-synuclein (SNCA), parkin(PARK2), and ubiquitin carboxy-terminal hydrolase L1(UCHL1) genes, have been identified as causative genes for familial PD. The B mutation of CYP2D6 gene(CYP2D6*4 allele) is a genetic risk factor for PD. Lewy body(LB), that is an intracellular inclusion body characteristic of PD, is widely distributed in the cerebral cortex of 20 to 30% of AD patients. This disease entity is called as Lewy body variant(LBV) of AD. LBV shares the genetic risk factor with AD and PD, i.e. APOE epsilon 4 allele and CYP2D6 B mutation. Gene diagnosis is possible for familial AD and PD. APOE and CYP2D6 genotyping is also applicable to the future prediction of AD and PD, respectively.

Alzheimer Disease↗
PubMed1991

[A case of recurrent cranial neuropathy presenting as recurrent Tolosa-Hunt syndrome].

A 64-year-old woman, with history of hypertension and arteriosclerosis, developed left painful ophthalmoplegia in July, 1988. Neurological examination proved abnormality of the third cranial nerve innervation, otherwise normal. No systemic illness was present. With corticosteroid therapy, the symptoms regressed and completely disappeared in 3 months. In January, 1990, right painful ophthalmoplegia appeared. Neurological examination revealed involvement of right sixth nerve and first branch of the right fifth nerve. With corticosteroid therapy, the symptoms completely regressed in several weeks. In April, 1990, she developed severe pain in the right side of the face. The facial pain disappeared rapidly with corticosteroid therapy, but reappeared following quit of steroid. She complained of severe pain of the right face, the territory of first and second branch of the right fifth nerve, but neurological examination was negative. With corticosteroid therapy, the pain disappeared remaining with mild tingling sensation on the right face, but during the tapering of corticosteroid in August, a severe peripheral type right facial palsy developed. Corticosteroid therapy resumed and the facial palsy regressed almost completely in ten days. Our case suggests that THS might be a variant of so-called recurrent cranial neuropathy.

Aged↗
PubMed1990

[Towards the development of an in vivo study model of Alzheimer-type neurofibrillary degeneration].

Progress in the search for the cause of Alzheimer's disease is considerably hampered by the lack of animal or in vitro model. We have shown that in Alzheimer's disease two pathological variants of Tau proteins, called Tau 64 and Tau 69, are regularly present in neural tissue undergoing neurofibrillary degeneration. Beside their diagnostic value, Tau 64 and Tau 69 might enable such a model to be devised at long last. It now seems possible to investigate for biochemical disorders capable of inducing the emergence of these two Tau proteins in neuron cultures or among transgenic animals. The innumerable pathogenetic tracks of Alzheimer's disease (aluminium, zinc, superoxide dismutase and free radicals, proteases and antiproteases, beta protein A4 precursor, etc.) should then be opened to exploration.

Alzheimer Disease↗
PubMed1989

[The pathogenic effect of human immunodeficiency virus. Molecular biological results].

Recent data suggest that the pathogenicity of HIV is mediated by the production of metabolised viral components which act as hormones. In particular the replication and maturation of T-lymphocytes, and the cellular interaction of immunocompetent cells and nerve cells are affected. The recognition of HIV by the immune system and consequently also the progression of the disease, is influenced by the HLA-type (DR-1) of the infected person. Replication of HIV may be accelerated by the simultaneous presence of other viruses (i.e. cytomegalovirus). So-called apathogenic, attenuated HIV variants have been described.

Acquired Immunodeficiency Syndrome↗