Molecular genetic evidence for common pathogenesis of childhood and adult Wilms' tumor

A case of Wilms' tumor in an adult is reported, showing, by restriction fragment length polymorphism analysis of somatic and tumor DNA, the loss of alleles from the short arm of chromosome 11. Loss of alleles in this region has previously been reported in childhood Wilms' tumor. The findings of this study indicate that adult Wilms' tumor and childhood Wilms' tumor may share a common pathogenic pathway. These results may also be useful in differentiating between Wilms' tumor and renal cell carcinoma or sarcoma in adults when the histologic findings are unclear.     

PCR amplification introduces errors into mononucleotide and dinucleotide repeat sequences.

The polymerase chain reaction (PCR) is used universally for accurate exponential amplification of DNA. We describe a high error rate at mononucleotide and dinucleotide repeat sequence motifs. Subcloning of PCR products allowed sequence analysis of individual DNA molecules from the product pool and revealed that: (1) monothymidine repeats longer than 11 bp are amplified with decreasing accuracy, (2) repeats generally contract during PCR because of the loss of repeat units, (3) Taq and proofreading polymerase Pfu generate similar errors at mononucleotide and dinucleotide repeats, and (4) unlike the parent PCR product pool, individual clones containing a single repeat length produce no "shadow bands". These data demonstrate that routine PCR amplification alters mononucleotide and dinucleotide repeat lengths. Such sequences are common components of genetic markers, disease genes, and intronic splicing motifs, and the amplification errors described here can be mistaken for polymorphisms or mutations.     

Protection against pneumococcal infection in mice conferred by phosphocholine-binding antibodies: specificity of the phosphocholine binding and relation to several types.

Some anti-phosphocholine antibodies protect mice against challenge with certain, but not all, pneumococcal types. We found that both their isotype and reactivity with the cell wall C-polysaccharide of encapsulated pneumococci, as measured by immunodiffusion, were important in predicting the protective activity of anti-phosphocholine antibodies. We propose that the specificity of the protective antibodies includes the backbone of the phosphocholine-containing structure.     

Cyclospora cayetanensis infection in Lagos, Nigeria

Although reports of Cyclospora infection continue to increase globally, few cases have been reported from the African continent. We present 11 cases of cyclosporiasis detected from stool samples submitted to seven major hospital laboratories in Lagos, Nigeria between March 1999 and April 2000.     

Parathyroid hormone related protein in hypercalcaemia of Hodgkin''s disease.

The role of parathyroid hormone related protein (PTHRP) as a humoral mediator of hypercalcaemia was investigated in a patient with lymphocyte depleted Hodgkin's disease during an episode of hypercalcaemia, using an immunohistochemical staining technique for PTHRP on the tumour tissue and an immunoradiometric (IRMA) assay for PTHRP1-86 on the patient's plasma. The plasma PTHRP was less than 0.23 pmol/l in the range found in normocalcaemic controls, and the immunohistochemical staining was not positive for protein. PTHRP did not have a role in the pathogenesis of hypercalcaemia in this patient.     

Increase of glycocalyx and altered lectin agglutination profiles of Pasteurella haemolytica A1 after incubation in bovine subcutaneous tissue chambers in vivo or in ruminant serum in vitro.

Pasteurella haemolytica serotype A1 (bovine strain OK) was incubated for 2 and 6 h in bovine subcutaneous tissue chambers in vivo, and ovine strain 82-25 and bovine strain L011 were incubated in vitro for 2 h in heat-inactivated ovine or bovine serum from which gamma globulin had been depleted by protein G affinity chromatography to assess changes in morphology and lectin agglutination profiles (strains 82-25 and L101 only). Cells, removed from chambers after 2 h, were covered with an extensive, dense glycocalyx extending approximately 0.5 microm from the cell surface. In many cells, the glycocalyx was separated from the cell surface by a clear, electron-transparent area. Cells, removed at 6 h, were covered with a sparse glycocalyx of fine fibers 0.2 to 0.3 microm from the cell surface. Strains 82-25 and L101, incubated for 2 h in heat-inactivated ovine or bovine serum or in heat-inactivated ovine or bovine serum depleted of gamma globulin by protein G affinity chromatography, were also covered with a glycocalyx. The glycocalyx did not bind protein A-colloidal gold and therefore did not contain aggregates of accumulated antibody. Strains 82-25 and L101 were incubated individually for 2 h in 10 mM sodium phosphate buffer (pH 7.2) containing 0.14 M NaCl, 0.5 mM CaCl2, and 0.15 mM MgCl2 or with this buffer and either 25% heat-inactivated, gamma globulin-depleted ovine serum or 25% heat-inactivated, gamma globulin-depleted bovine serum. Agglutination profiles were then determined with 17 lectins in 10 mM HEPES-buffered saline (pH 8.4) with 0.1 mM CaCl2 and 0.08% sodium azide. Profiles did not vary with 10 of 17 lectins. However, profiles did vary with peanut agglutinin, Phaseolus vulgaris leucoagglutinin, Sophora japonica agglutinin, Maackia amurensis lectin II, Narcissus pseudonarcissus (daffodil) lectin, Griffonia simplicifolia lectin I, and Pisum sativum agglutinin. Altered profiles indicate a change in the bacterial cell surface, possibly by adsorption or alteration of surface carbohydrate moieties by serum constituents.     

The protective effect of ipratropium bromide aerosol against bronchospasm induced by hyperventilation and the inhalation of allergen, methacholine and histamine

The ability of the anticholinergic agent, ipratropium bromide, Atrovent, (40 mcg from a metered dose inhaler) to prevent bronchoconstriction produced by four different provocation tests was compared with placebo in 12 asthmatic patients. The provocation tests used were hyperventilation and inhalations of histamine, methacholine and an allergen to which the subject was known to be sensitive. The order in which each patient received the tests was determined according to a Latin-square design and remained the same on both test days. Pretreatment with ipratropium bromide and placebo was allocated randomly and administered in double-blind fashion. Ipratropium bromide provided significant protection at the 5% level against all four types of challenge. The average number of breaths required to produce a fall of at least 20% in FEV1 (forced expiratory volume in one second) was doubled for both histamine and allergen and increased by a factor of six for methacholine. The fall in FEV1 induced by hyperventilation was approximately halved. No side effects were noted with ipratropium bromide.