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Biomedical subjects

P Small

Publications and source records attributed to P Small.

86 records · Page 5Linked to original sources
PubMed1976

Leukocytoclastic vasculitis.

Patients with leukocytoclastic vasculitis have purpuric, palpable lesions, most commonly on the lower part of the legs. Systemic involvement, particularly of the kidneys, is found frequently. Characteristic pathological features include necrosis of small vessels within the dermis, infiltration by polymorphonuclear leukocytes within and around the vessel walls, hemorrhage, and occasionally thrombosis. Immunofluorescence study frequently shows granular deposits of immunoglobulins and complement in vessel walls. Etiologic agents that have been implicated include infection, foreign proteins, chemicals, drugs, and a variety of diseases. The mechanism causing tissue damage is thought to be mediated by immune complexes, although specific antigens have only occasionally been unequivocally identified. Treatment includes bedrest, corticosteroids, and sometimes, cytotoxic agents.

Animals↗
PubMed1975

Human necrotizing vasculitis: immunoglobulins and complement in vessel walls of cutaneous lesions and normal skin.

Immunoglobulins and C3 were detected by immunofluorescence in the blood vessel walls of biopsies of clinically normal skin in patients with active necrotizing vasculitis. Of the 13 patients studied, 9 had C3 and 6 of these had IgM or IgA in biopsies of lesions of vasculitis. In adjacent clinically normal skin, 7 patients had C3 and 3 of these also had IgM or IgA. These findings support the hypothesis that immunoglobulins and complement are present in vessels of some patients prior to chemotaxis of polymorphonuclear leukocytes and the resulting inflammatory purpuric lesions so characteristic of necrotizing vasculitis.

Antigen-Antibody Complex↗
PubMed1975

The nature and significance of sheep red blood cell rosettes.

Rosette formation between human thymus-derived (T) lymphocytes and sheep red blood cells (SRBC) was inhibited by T cell specific antisera but not by sera directed against other lymphocyte antigens. We conclude that the SRBC receptor is closely linked to T specific antigens.

Adsorption↗
PubMedDate not supplied

Cross-sectional study of skeletal maturation in normal children from Nottingham and London.

The TW2 method (Tanner et al. 1975) was used to evaluate skeletal maturation in 173 children from Nottingham and 120 children from London WC1 . All of the children from Nottingham had hand-wrist injuries and were attending the Accident and Emergency Department of the Children's Hospital, Nottingham. The London children were all a part of a longitudinal growth study, which started in 1952-1953. When compared with the TW2 centiles, the Nottingham children showed retardation, and the London children advancement in skeletal maturation.

Adolescent↗
PubMedDate not supplied

A molecular strategy for the study of bacterial invasion.

Bacterial populations are often clonal, and even within a bacterial species, the frequency of gene exchange and recombination is quite low. Consequently, mobile genetic elements--plasmids, bacteriophages, and transposons--have been the central factors in the evolution of pathogenic traits. One central feature of pathogenicity, the capacity to enter epithelial cells, is encoded by the bacterial chromosome of Yersinia pseudotuberculosis but by plasmid genes in enteroinvasive Escherichia coli. A single Yersinia gene, inv, which encodes a single 107,000-dalton protein, can be cloned in E. coli K12, and its presence is sufficient to permit the bacteria to enter cultured human cells. In contrast, fully 70 kilobases of a virulence plasmid from enteroinvasive E. coli must be transferred to E. coli K12 to achieve the same result. While researchers are at the early stages of understanding microbial entry into host cells, they can now investigate the molecular basis of this event in greater detail than has previously been possible.

Animals↗
PubMedDate not supplied

[Drug resistance of Mycobacterium tuberculosis in Orizaba, Veracruz. Implications for the tuberculosis prevention and control program].

BACKGROUND: Tuberculosis, declared a global emergency by the World Health Organization, continues to be an important public health problem in Mexico, included in the first twenty causes of death. OBJECTIVE: To know the impact of drug resistance of Mycobacterium tuberculosis on treatment outcome, need of re-treatment and mortality in a cohort of patients with pulmonary tuberculosis receiving directly observed therapy, short course (DOTS). METHODS: We conducted a population-based study in a suburban region in Southern Mexico. People who had been coughing for more than two weeks underwent sputum acid-fast bacilli smear. Patients with a positive smear were recruited and underwent clinical exam, chest X-ray, HIV testing, and sputum cultures. Identification, drug susceptibility testing and restriction fragment length polymorphism analysis (RFLP) were performed in all isolates. Patients were followed every 12 months for new episodes of tuberculosis and vital status. Patients were referred for clinical care to the local program of tuberculosis. Deaths were corroborated with death certificates. Informed consent was obtained from participants. RESULTS: Between March 1995 and February 1999, tuberculosis was diagnosed in 371 patients who were followed for an average of 32 months. M. tuberculosis was cultured from 316 patients; resistance to any drug occurred in 25.0% of isolates (primary 18.8%, acquired 49.2%); only to isoniazid in 6.8% (primary 7.3%, acquired 4.8%); to isoniazid and rifampin in 6.2% (primary 1.6%, acquired 23.8%). Patients with drug resistance had a higher probability of treatment failure (OR = 16.9, CI 95% 4.5-63.0) and patients with MDR strains had a higher probability of need of re-treatment (RR = 24.4, CI 95% 8.8-67.6), and of death (RR = 4.0, CI 95% 1.5-10.7). Additional variables were found to be associated with subsequent episodes of disease and mortality: Cocaine use, chronic disease, type of radiological lesions, HIV co-infection, non-compliance and treatment delay, as well as RFLP clustering. CONCLUSIONS: In this study, we observed that drug resistance showed a severe impact on the outcome and survival; drug-resistance was the most significant factor for these negative outcomes; DOTS may not be sufficient in areas where drug resistance is considerable, and patient follow-up for longer periods of time, as compared to evaluation at the end of treatment, provides additional information which is useful for prevention and control programs.

Adult↗
PubMedDate not supplied

Wegener's granulomatosis and relapsing polychondritis: a case report.

Relapsing polychondritis, a rare disorder characterized by inflammation of cartilaginous tissue, is often associated with vasculitic features. Wegener's granulomatosis is an uncommon form of vasculitis, usually responsive to treatment with cyclophosphamide. A 59-yr-old man with relapsing polychondritis, initially well controlled by corticosteroid therapy, developed pulmonary infiltrates and glomerulonephritis. After pathological confirmation of Wegener's granulomatosis, cyclophosphamide therapy was instituted and remission achieved.

Cyclophosphamide↗