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PubMed1998

Genotyping HIV-1 and HCV strains by a combinatorial DNA melting assay (COMA).

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) strains can be genetically classified into genetic lineages known as genetic types or subtypes according to phylogenetic analyses of complete or partial nucleotide sequences of their genomes. The genetic classification of HIV-1 and HCV strains has important implications for the development of globally effective vaccines and for the management of patients. MATERIALS AND METHODS: A new method, termed combinatorial DNA melting assay (COMA), allows rapid accessing of comparative genetic information between related DNA sequences, making it possible to rapidly and accurately genotype unknown HIV-1 and HCV strains. COMA is mainly based on the differential melting properties of long DNA heteroduplexes. Combinatorial arrays of DNA heteroduplexes are formed when captured PCR-amplified reference DNA with known nucleotide sequences are combined with solution-phase complementary and antigenically labeled DNA with unknown sequences. Genetic divergence between the known and the unknown sequences is inferred as the experimentally derived melting curves of the two strands of the DNA heteroduplexes increasingly diverge. RESULTS: COMA was successfully applied to the genetic classification of HIV-1 and HCV strains into phylogenetic lineages or subtypes. CONCLUSIONS: Use of this assay should accelerate current efforts to understand the global molecular epidemiology of HIV-1 and HCV and may extend to the genetic characterization of other genetically diverse infectious pathogens associated with numerous diseases.

Base Composition↗
PubMed2005

Pathogenic mutations and polymorphisms in the lipoprotein receptor-related protein 5 reveal a new biological pathway for the control of bone mass.

PURPOSE OF REVIEW: This review summarizes recent findings concerning the genomic variations of the lipoprotein receptor-related protein 5 (LPR5) in relation to bone biology. RECENT FINDINGS: Mutations in the LRP5 gene causing high bone mass (HBM) and osteoporosis-pseudoglioma (OPPG) underscored the role of the Wnt-LRP5 canonical signaling on bone formation. Additional LRP5 activating mutations have been identified in a variety of sclerosing bone dysplasias, improving the diagnostic classification of these disorders. Association of polymorphisms in LRP5 with bone mineral density indicate that LRP5 genetic variation contribute to the risk of osteoporosis. Transgenic mice carrying the LRP5 HBM mutation have improved bone biomechanical properties, and the molecular mechanisms by which this mutation exerts its effects have been clarified. A number of KO mice have shown the complex effects of the Wnt-LRP5 pathway on bone mass and skeletal morphology. In vitro studies indicate that osteoblasts produce a variety of Wnts, the LRP5 co-receptor frizzled (Fzd), as well as LRP5 and Wnt inhibitors, i.e. dickkopf (Dkk1) and frizzled-related proteins (Sfrps), respectively, and delineate the role of these molecules in regulating the commitment of mesenchymal stem cells along the osteoblastic lineage. SUMMARY: Identification of pathogenic mutations and allelic variations in LRP5 has improved our understanding of the physiology of bone mass acquisition and the pathophysiology of several bone diseases, including osteoporosis. Understanding how complex interactions between agonistic and inhibitory factors in the Wnt-LRP5 canonical pathway influence osteoblast functions has the potential of providing new anabolic treatments for osteoporosis.

Alleles↗
PubMed1998

Seizures: classification, etiologies, and pathophysiology.

Epilepsy is a disorder of recurrent seizures that are neural in origin. Partial seizures are usually due to a structural cerebrocortical lesion and may be simple or complex. Brain injuries may alter inherent neuronal properties and neuronal circuits and lead to recurrent excitatory activity. Potentiation of excitatory synapses and depression of inhibitory synapses are probable critical events in epileptogenesis. The pathogenic factors underlying primary or idiopathic generalized seizures are not as well understood. A more diffuse or multifocal state of neuronal excitability may be the result of early congenital events that are magnified over time. The progression of subclinical neuronal excitatory activity to a clinical seizure may relate directly to the phenomenon of cortical plasticity.

Animals↗
PubMed2003

Pathophysiology of priapism: dysregulatory erection physiology thesis.

PURPOSE: While a modest amount of medical literature has been written on the topic of priapism, reports heretofore have focused predominantly on diagnostic and management related aspects of the disorder, providing meager information in regard to its pathophysiology. Accordingly the intent of this review was to explore the etiological and pathogenic factors involved in priapism. MATERIALS AND METHODS: The review entailed an overview of traditional and modern concepts that have been applied to the pathophysiology of priapism and an evaluation of assorted observational and experimental data relating to this field of study. The basic exercise consisted of a literature search using the National Library of Medicine PubMed Services, index referencing provided through the Historical Collection of the Institute of Medicine of The Johns Hopkins University and a survey of abstract proceedings from national meetings relevant to priapism. RESULTS: Insight into the pathophysiology of priapism was derived from a synthesis of evolutionary clinical experiences, mythical beliefs, clinical variants and scientific advances associated with the field of priapism. The results can be summarized. 1) Clinicopathological manifestations of priapism support its basic classification into low flow (ischemic) and high flow (nonischemic) hemodynamic categories, commonly attributed to venous outflow occlusion and unregulated arterial overflow of the penis, respectively. 2) Factual information is insufficient to substantiate etiological roles for urethral infection, bladder distention, failed ejaculation, satyriasis and sleep apnea in priapism. 3) Features of the variant forms of priapism invoke changes in nervous system control of erection and penile vascular homeostasis as having pathogenic roles in the disorder. 4) Clinical therapeutic and basic science investigative studies have revealed various effector mechanisms of the erectile tissue response that may act in dysregulated fashion to subserve priapism. CONCLUSIONS: This exercise suggested that, while priapism is commonly defined in terms of adverse mechanical contexts affecting penile circulation, it may also be viewed at least in some situations as an unbalanced erectile response involving derangements in possibly diverse systems of regulatory control. An integrative scientific approach that encompasses tissular, cellular and molecular levels of investigation may allow further understanding of the pathophysiology of the disorder. Ongoing elucidation of this pathophysiology can be expected to promote the development of new priapism therapies.

Greece, Ancient↗
PubMed2003

Pregnancy complications of the antiphospholipid syndrome.

Starting from their first description, antiphospholipid antibodies (aPL) were associated with repeated miscarriages and fetal losses. Other complications of pregnancy like preterm birth,with pre-eclampsia or severe placental insufficiency were also frequently reported and are included in the current classification criteria of the antiphospholipid syndrome (APS). The titre, the isotype of the antibodies or their antigen specificity may be important in the risk level determination. Some of the difference in the reported results can be explained by the poor standardization achieved in aPL testing or by the not univocal classification of pregnancy complications. The pathogenesis of pregnancy failures is linked to the thrombophilic effect of aPL but also to different mechanisms including a direct effect of antibodies on the throphoblast differentiation and invasion. The study of experimental animal models provided sound evidence of the pathogenic role of aPL both in lupus prone and naive mice. The definition of APS as a condition linked to high obstetric risk and the application of an effective therapy have completely changed the prognosis of pregnancy in these patients. In fact, despite the high number of complications and preterm delivery, today a successful outcome can be achieved in the large majority of the cases.

Abortion, Spontaneous↗
PubMed1996

Dysregulation of the polymorphonuclear leukocyte--Candida spp. interaction in HIV-positive patients.

OBJECTIVE: In HIV-infected patients there is an increased frequency of fungal infections. Dysregulation of the response of phagocytic cells to fungal pathogens may be involved. DESIGN: Phagocytosis of Candida spp., consecutive intracellular production of reactive oxygen species, and candicidal activity were analysed in polymorphonuclear leukocytes (PML) from HIV-1-infected patients, who were at stage C3 of the 1993 revised Centers for Disease Control and Prevention classification system, by means of flow cytometry. METHODS: Phagocytic ability was assessed by measuring uptake of fluorescein isothiocyanate-labelled Candida albicans, C. krusei and C. glabrata. Reactive oxygen intermediate production was estimated by the quantity of dihydrorhodamine-123 converted to rhodamine-123 intracellularly. The candicidal effect was assessed by the propidium iodide uptake of killed yeast cells. RESULTS: As compared to PML of healthy, HIV-negative controls, PML of AIDS patients exhibited an increased phagocytic activity and a similar ability to generate reactive oxygen products. In contrast, PML of AIDS patients displayed a decreased candicidal activity (P < 0.05 compared to controls). CONCLUSION: These results suggest that in patients with advanced HIV-1 infection the impairment of non-oxidative killing mechanisms of phagocytic cells may contribute to the high incidence of fungal infections.

Adolescent↗
PubMed1994

Lyme disease.

In the United States, Lyme disease is the most common arthropod-borne infection. The majority of cases occur in the Northeast, the Midwest, and California, which are areas with established foci of Borrelia burgdorferi. Phenotypic and genotypic diversity of B. burgdorferi has resulted in its classification into three separate genospecies and may account for differences in disease expression. Clinical features of Lyme disease have expanded to include a flulike illness without erythema migrans and the persistence of intrathecal antibody responses after successful antibiotic therapy in neuroborreliosis. Better understanding of the pathogenic mechanisms of Lyme arthritis will help guide future treatment decisions, and recent progress made in assessing the risk of infection from tick bites and vaccine development may help calm public anxiety about Lyme disease.

Arthritis, Infectious↗
PubMed1997

Use of heteroduplex analysis to classify legionellae on the basis of 5S rRNA gene sequences.

Seventeen different species of Legionella, 12 serogroups of Legionella pneumophila, and 2 Legionella-like amoebal pathogens (LLAP1 and Sarcobium lyticum) were examined by heteroduplex analysis of PCR products of the 5S rRNA gene. Eight different banding patterns were identified, indicating that heteroduplex analysis of this gene can be used to classify these bacteria according to base substitutions between species. This classification may have future applications in clinical and epidemiological studies.

Bacterial Typing Techniques↗
PubMed2006

Sensitive detection of KIT D816V in patients with mastocytosis.

BACKGROUND: The 2447 A > T pathogenic variation at codon 816 of exon 17 (D816V) in the KIT gene, occurring in systemic mastocytosis (SM), leads to constitutive activation of tyrosine kinase activity and confers resistance to the tyrosine kinase inhibitor imatinib mesylate. Thus detection of this variation in SM patients is important for determining treatment strategy, but because the population of malignant cells carrying this variation is often small relative to the normal cell population, standard molecular detection methods can be unsuccessful. METHODS: We developed 2 methods for detection of KIT D816V in SM patients. The first uses enriched sequencing of mutant alleles (ESMA) after BsmAI restriction enzyme digestion, and the second uses an allele-specific competitive blocker PCR (ACB-PCR) assay. We used these methods to assess 26 patients undergoing evaluation for SM, 13 of whom had SM meeting WHO classification criteria (before variation testing), and we compared the results with those obtained by direct sequencing. RESULTS: The sensitivities of the ESMA and the ACB-PCR assays were 1% and 0.1%, respectively. According to the ACB-PCR assay results, 65% (17/26) of patients were positive for D816V. Of the 17 positive cases, only 23.5% (4/17) were detected by direct sequencing. ESMA detected 2 additional exon 17 pathogenic variations, D816Y and D816N, but detected only 12 (70.5%) of the 17 D816V-positive cases. Overall, 100% (15/15) of the WHO-classified SM cases were codon 816 pathogenic variation positive. CONCLUSION: These findings demonstrate that the ACB-PCR assay combined with ESMA is a rapid and highly sensitive approach for detection of KIT D816V in SM patients.

Cell Line, Tumor↗
PubMed1977

Characterization of Escherichia coli serogroups causing meningitis, sepsis and enteritis. II. Classification of Escherichia coli O78 strains by phage sensitivity, colicin type and antibiotic resistance.

Escherichia coli O78: K80 strains isolated from an outbreak of meningitis, sepsis and enteritis in infants, were compared with O78: K80 strains from sporadic cases of enteritis, healthy carriers and animals. The strains were uniform in antigenic structure and phage pattern but differed in colicinogenicity. The epidemic strains and calf-pathogenic cultures produced colicin V, the remaining isolates were characterized by other types of colicin or were not colicinogenic. Col V+ strains multiplied in the mouse peritoneal cavity more readily and killed the animals at significantly lower doses than did col V- strains. One half of antibiotic resistant O78: K80 strains carried R factor. The spread of R factor could be followed by phage restriction experiments.

Animals↗
PubMed1996

Rapid identification of bacteria by direct matrix-assisted laser desorption/ionization mass spectrometric analysis of whole cells.

Several characteristic ions were observed during the direct analysis of a variety of both gram-negative and gram-positive intact bacterial cells by the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) technique. The entire process, involving absolutely no sample processing, could be completed in less than ten minutes. A number of specific biomarkers, generated reproducibly for each type of cell from the corresponding mass spectrum, permitted the identification, as well as the distinction, of pathogenic bacteria from their non-pathogenic counterparts. In addition, individual strains of a specific organism could also be differentiated easily. Some of these biomarkers correspond to those observed earlier during the MALDI-MS analysis of protein extracts of the same bacteria. This approach, which can yield valuable data for rapid classification and detection of microorganisms, represents a substantial breakthrough for rapid screening of environmental as well as biological samples.

Bacteria↗
PubMed2001

Neuropsychiatric lupus.

Neuropsychiatric (NP) manifestations of systemic lupus erythematosus (SLE) have been recognized for more than 100 years but continue to pose a diagnostic and therapeutic challenge for rheumatologists and other physicians involved in the care of SLE patients. NP-SLE includes a plethora of clinical manifestations and the reported prevalence has varied widely between 14% and 75%. The recent introduction of a standard nomenclature, case definitions, and diagnostic criteria for 19 NP-SLE syndromes should facilitate a more consistent approach to the classification of patients and to the execution of large multicenter clinical studies. The etiology of NP-SLE is likely multifactorial and includes microangiopathy, autoantibody production, and the intrathecal production of proinflammatory cytokines. Newer imaging modalities of brain structure and function provide novel ways of understanding pathogenic mechanisms. The use of standardized neuropsychometric techniques to evaluate cognitive function has identified a high prevalence of cognitive impairment in SLE patients. The management of patients with NP-SLE includes symptomatic and immunosuppressive therapies, evidence for which is largely limited to uncontrolled clinical trials and anecdotal experience. Multicenter initiatives are required to address important issues on prognosis and management.

Cognition Disorders↗
PubMed2004

Mitochondrial medicine.

After reviewing the history of mitochondrial diseases, I follow a genetic classification to discuss new developments and old conundrums. In the field of mitochondrial DNA (mtDNA) mutations, I argue that we are not yet scraping the bottom of the barrel because: (i) new mtDNA mutations are still being discovered, especially in protein-coding genes; (ii) the pathogenicity of homoplasmic mutations is being revisited; (iii) some genetic dogmas are chipped but not broken; (iv) mtDNA haplotypes are gaining interest in human pathology; (v) pathogenesis is still largely enigmatic. In the field of nuclear DNA (nDNA) mutations, there has been good progress in our understanding of disorders due to faulty intergenomic communication. Of the genes responsible for multiple deletions and depletion of mtDNA, mutations in POLG have been associated with a great variety of clinical phenotypes in humans and to precocious aging in mice. Novel pathogenetic mechanisms include alterations in the lipid milieu of the inner mitochondrial membrane and mutations in genes controlling mitochondrial motility, fission, and fusion.

Animals↗
PubMed1995

[Immunologic hemolytic anemia. From autoimmunity to anti-medication immunization].

The serological investigation of auto-immune hemolytic anemias based on the direct antiglobulin test, the study of the serum and the eluate allows a classification of the auto-immune hemolytic anemia which is still valid and correlates well with the clinical features. The use of new techniques should increase the sensitivity of the tests but also stress the problem of the frontier between physiological and pathological states. The use of monoclonal antibodies of defined specificity would be an useful tool for the immunohematological classification of the auto-immune hemolytic anemias. The addition of new therapeutical means should improve the prognosis of these anemias. The increasing consumption of drugs and the development of the investigations of the adverse reactions including the hemolytic anemias have allowed the emergence of new pathogenic concepts. The gravity of the clinical evolution of some of these immune hemolytic anemias stress the necessity of an adequate therapeutic survey and the development of new means of diagnostic. The clinicians should be aware of the possibility of cross reactivity for drug dependent antibodies with other components of related chemical structure.

Anemia, Hemolytic, Autoimmune↗
PubMed2000

A new bacteriophage, VHML, isolated from a toxin-producing strain of Vibrio harveyi in tropical Australia.

Some strains of Vibrio harveyi are known to be pathogenic for fish and many invertebrates including crustaceans. Despite their importance, their modes of virulence have yet to be fully elucidated. Here, we present a previously unreported bacteriophage extracted from a toxin-producing strain of V. harveyi isolated from moribund prawn larvae in tropical Australia. Classification into the family Myoviridae was based upon morphological characteristics (an icosahedral head, a neck/collar region and a sheathed rigid tail) and nucleic acid characteristics (double-stranded linear DNA). We have termed the bacteriophage VHML (Vibrio Harveyi Myovirus Like). VHML is a temperate bacteriophage that has a narrow host range and shows an apparent preference for V. harveyi above other vibrios (63 Vibrio isolates tested) and other genera (10 other genera were tested). The conventional methods for phage concentration and extraction of nucleic acids from phage particles were not efficient and the alternative methods that were used are discussed.

Animals↗
PubMed1997

A practical guide to the diagnosis and management of bone and joint infections.

Infectious arthritis arises from haematogenous spread of organisms through the synovial membrane or from the direct extension of a contiguous infection. The diagnosis rests on the isolation of the pathogen(s) from joint fluid obtained by aspiration or from debridement. Synovial fluid analysis and Gram stains provide clues to the aetiology. The treatment of septic arthritis includes appropriate antimicrobial therapy and joint drainage. Bone infections are currently classified by the Waldvogel or Cierny-Mader classification. Cierny-Mader staging allows stratification and development of comprehensive treatment guidelines for each stage. Osteomyelitis therapy emphasises early diagnosis and aggressive treatment. Radiographs and bone cultures are the mainstays of diagnosis. Radionuclide scans, computerised tomography or magnetic resonance imaging may be obtained when the diagnosis of osteomyelitis is equivocal or to help gauge the extent of the infection. Medical therapy includes improving any host deficiencies, initial antibiotic selection and antibiotic modification based on culture results. Surgical treatment involves debridement of necrotic bone and tissue, obtaining appropriate cultures, managing dead space and, when necessary, obtaining bone stability.

Arthritis, Infectious↗
PubMed1975

[The bacteriological diagnosis of vibrio fetus infection in man (author's transl)].

A synopsis of the present classification of Vibrio fetus is given (tab. 1, 2). Besides the presentation of the importance of these bacteria in veterinary medicine, 97 human infections have been published up to now. The geographic, age and sex distribution of these cases and the material out of which the pathogens were isolated is presented (tab. 3, 4). The clinical picture is summarized. For the culture of Vibrio fetus liver broth as described by TAROZZI incubated for at least 3-4 days was suitable as enrichment medium. The necessity of a prolonged incubation period was shown by results of continous registration of the optical density of growing Vibrio fetus cultures (fig. 1). If specimen is plated out on solid culture media before enrichment, the suitable media are chocolate agar, brain-heart infusion and Bacto-tryptose agar. For subcultures the DST-agar is also useful. Solid media cultures should be incubated microaerobically with 10% CO2 added. The resistance to Cephalothin of Vibrio fetus can be applied for selection on solid culture media. The metabolic activities of different Vibrio fetus biotypes were compared. A hitherto not reported metabolic activity, the hydrolysis of palmitic acid ester, is described (tab. 5). In the tube dilution test Vibrio fetus strains were sensitive to Gentamycin, Streptomycin, Ampicillin, Ciclacillin and Carbenicillin. They were resistent to Penicillin G, Cephalotin and Sulfonamid and showed borderline sensitivities to Tetracyclin, Kanamycin and Chloramphenicol (tab. 6).

Ampicillin↗
PubMed1994

[The clinico-morphological classification of changes in the microcirculatory bed].

An autopsy-based study was made of the microcirculatory bed (MCB) of human heart in ischemic heart disease and arterial hypertension in an age-related aspect. Changes in MCB and its time course were studied in experimental models. On the basis of the studies done and data from the published literature we elaborated a morphological classification of MCB which include the following stages: compensatory; initial pathologic changes with the adaptation being maintained at the same level as before; profound pathological changes at the background of lowered adaptation; decompensation. The classification outlined above may be used in examining autopsy and biopsy material (experimental or perioperative) as well as in clinical investigations designed to study the nail bed, bulbar, conjunctiva, rectal mucous membrane. Investigation into MCB changes will enable us to properly assess adaptive potential and prescribe pathogenically substantiated surgical, internal or complex health resort treatment.

Adaptation, Physiological↗