Immunocytochemical staining of cells in pleural and peritoneal effusions with a panel of monoclonal antibodies.

A panel of seven monoclonal antibodies was applied to smears of cell deposit from 70 pleural and peritoneal fluids, using an immunoalkaline phosphatase (IAP) procedure. The cases were chosen to show typical cytological patterns, both benign and malignant, and in this way the diagnostic value of the method could be assessed. The antibodies used were 2D1 (anti-leucocyte), Ca 1, HMFG-2 (anti-milk fat globule membrane), LE61 and M73 (both anti-intermediate filament antibodies), anti-CEA, and K92 (anti-keratin). The anti-leucocyte antibody was found useful for distinguishing lymphoma from carcinoma. Anti-CEA gave positive reactions in 80% of carcinoma cases and was not seen to react with any other cell types. Ca 1 was positive with some cells in 95% of carcinoma cases, but mesothelial cells reacted with it in two cases. A strong reaction with the anti-milk fat globule membrane antibody was very constant in carcinoma but was also seen in mesothelial cells in 30% of benign effusions. The anti-keratin reacted with malignant cells in only a small proportion of cases. The antibodies against epithelial intermediate filaments reacted equally strongly with benign mesothelial cells and carcinoma cells, but gave negative reactions with lymphoma cells. It is concluded that a suitably chosen panel of monoclonal antibodies can be of great value in identifying neoplastic cells in serous effusions.     

RS1 element of Vibrio cholerae can propagate horizontally as a filamentous phage exploiting the morphogenesis genes of CTXphi.

In toxigenic Vibrio cholerae, cholera toxin is encoded by the CTX prophage, which consists of a core region carrying ctxAB genes and genes required for CTXPhi morphogenesis, and an RS2 region encoding regulation, replication, and integration functions. Integrated CTXPhi is often flanked by another genetic element known as RS1 which carries all open reading frames (ORFs) found in RS2 and an additional ORF designated rstC. We identified a single-stranded circularized form of the RS1 element, in addition to the CTXPhi genome, in nucleic acids extracted from phage preparations of 32 out of 83 (38.5%) RS1-positive toxigenic V. cholerae strains analyzed. Subsequently, the corresponding double-stranded replicative form (RF) of the RS1 element was isolated from a representative strain and marked with a kanamycin resistance (Km(r)) marker in an intergenic site to construct pRS1-Km. Restriction and PCR analysis of pRS1-Km and sequencing of a 300-bp region confirmed that this RF DNA was the excised RS1 element which formed a novel junction between ig1 and rstC. Introduction of pRS1-Km into a V. cholerae O1 classical biotype strain, O395, led to the production of extracellular Km(r) transducing particles, which carried a single-stranded form of pRS1-Km, thus resembling the genome of a filamentous phage (RS1-KmPhi). Analysis of V. cholerae strains for susceptibility to RS1-KmPhi showed that classical biotype strains were more susceptible to the phage compared to El Tor and O139 strains. Nontoxigenic (CTX(-)) O1 and O139 strains which carried genes encoding the CTXPhi receptor toxin-coregulated pilus (TCP) were also more susceptible (>1,000-fold) to the phage compared to toxigenic El Tor or O139 strains. Like CTXPhi, the RS1Phi genome also integrated into the host chromosomes by using the attRS sequence. However, only transductants of RS1-KmPhi which also harbored the CTXPhi genome produced a detectable level of extracellular RS1-KmPhi. This suggested that the core genes of CTXPhi are also required for the morphogenesis of RS1Phi. The results of this study showed for the first time that RS1 element, which encodes a site-specific recombination system in V. cholerae, can propagate horizontally as a filamentous phage, exploiting the morphogenesis genes of CTXPhi.     

Effect of cetirizine on histamine- and leukotriene D4-induced bronchoconstriction in patients with atopic asthma.

Cetirizine, a derivative of hydroxyzine, is a new compound with potent antihistaminic property without antiserotonin and anticholinergic activities. The effect of both a single dose (15 mg) and 7 days of treatment (15 mg twice daily) with cetirizine, a potent H1 antagonist on bronchoconstriction induced by histamine and leukotriene D4 (LTD4) has been examined in 10 patients with mild atopic asthma in a placebo-controlled, double-blind, crossover study. Cetirizine, after a single dose and 7 days of treatment with placebo, the geometric mean values of the provocative concentration of histamine causing a 20% fall in FEV1 (millimolars) were 1.60 (95% confidence interval, 0.82 to 3.11) and 1.67 (0.77 to 3.65), compared with 118.07 (77.22 to 180.54) (p less than 0.0001) and 53.16 (20.50 to 137.84) after cetirizine administration (p less than 0.0002). The mean inhibition after a single dose was twofold higher than after 1 week of treatment (p less than 0.05). After a single dose and 7 days of treatment with placebo, the geometric mean values of the provocative concentration of LTD4 causing a 20% fall in FEV1 (micromolars) were 2.26 (1.74 to 2.94) and 2.37 (1.77 to 3.17), compared with 3.90 (2.60 to 5.86) (p less than 0.05) and 3.21 (2.28 to 4.52) after cetirizine administration. This result suggests that cetirizine is a potent H1 antagonist in the human airways. Diminished activity after 1 week of treatment suggests subsensitivity of H1 receptors developing in human airways. The small protective effect after a single dose against LTD4-induced bronchoconstriction indicates a nonspecific rather than a specific receptor antagonism.     

A new small temperate DNA phage BcP15 isolated from <Emphasis Type="Italic">Burkholderia cepacia</Emphasis> DR11

Summary. A Burkholderia cepacia DR11 strain was isolated during the survey of microorganisms from coastal water of deltaic Sunderbans. This strain always released temperate phage BcP15 into culture supernatant. UV irradiation of the strain also induced phage induction. The phage titer was 2.3 × 10⁸. New temperate phage BcP15 has unusual structure. It has a hexagonal head, 65 nm in diameter and a tail 200 nm long, attached with single thick wavy tail fiber (424–705 nm). Phage DNA is double stranded 11.9 kb long. Southern hybridization result indicated that the phage DNA was in lysogenic state into the B. cepacia DR11 genome. SDS-PAGE of phage protein showed two major bands of molecular weight 20 kDa and 40 kDa.     

Inhibition of synovial fluid lysosomal glycosidases by anti-Arthritic gold preparations

The ability of currently available anti-arthritic gold preparations to inhibit lysosomal glycosidases from rheumatoid synovial fluid and normal human serum was studied in vitro.It was shown that these preparations differ markedly in their ability to inhibit the enzymes. Gold thioglucose (Solganal) did not inhibit -glucuronidase (-GLUC), -N-acetylglucosaminidase (-NAG) or hyaluronidase (HASE). Chloro(triethylphosphine)gold (SK&F 36914) was a potent inhibitor of -NAG only. Sodium aurothiomalate (Myochrysine and sodium 3-aurothio-2-propanol-1-sulphonate (Allyochrisine) were inhibitors of all three enzymes, notably -GLUC.Kinetic analysis of inhibition by aurothiomalate demonstrated apparent competitive inhibition with -GLUC, but non-competitive inhibition with HASE and -NAG -GLUC was also strongly inhibited by silver and copper thiomalates.The concentrations of these drugs required for effective inhibition of lysosomal glycosidases probably exceed those attained in serum and therefore preclude this action extracellularly. It is suggested that durg sequestration and retention within phagocytic cells facilitates inhibition of glycosaminoglycan catabolism that mediates cleavage of glucuronidic linkages of hyaluronic acid and chondroitin sulphates.The hypothesis that gold dompounds act in vivo by attenuating the activity of lysosomal enzymes is discussed in relation to these and previous findings.     

The newer unconventional indications of permanent pacemakers

In recent years, the indications for permanent pacemakers have expanded. The interest has focussed on hypertrophic cardiomyopathy, dilated cardiomyopathy and a new entity called hypertensive hypertrophy with cavity obliteration (HHCO). Pacemaker therapy is establishing itself for the prevention of atrial fibrillation. Pacing for neurocardiogenic syncope with newer pacing mode has encouraging datas. Pacemaker for long QT syndrome, after cardiac transplant and for haemodynamic improvement in occasional cases of first degree atrio-ventricular block is getting attention. The AHA and ACC guidelines updated in 1998 for implantation of cardiac pacemakers, now include several of these newer indications.     

High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes

As more mutations are identified in genes of known sequence, there is a crucial need in the areas of medical genetics and genome analysis for rapid, accurate and cost-effective methods of mutation detection. We have developed a multiplex allele-specific diagnostic assay (MASDA) for analysis of large numbers of samples (> 500) simultaneously for a large number of known mutations (> 100) in a single assay. MASDA utilizes oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA samples are immobilized on a solid support and a single hybridization is performed with a pool of allele-specific oligonucleotide (ASO) probes. Any probes complementary to specific mutations present in a given sample are in effect affinity purified from the pool by the target DNA. Sequence-specific band patterns (fingerprints), generated by chemical or enzymatic sequencing of the bound ASO(s), easily identify the specific mutation(s). Using this design, in a single diagnostic assay, we tested samples for 66 cystic fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations, four mutations in Canavan disease, four mutations in Fanconi anemia, and five mutations in BRCA1. Each mutation was correctly identified. Finally, in a blinded study of 106 of these mutations in > 500 patients, all mutations were properly identified. There were no false positives or false negatives. The MASDA assay is capable of detecting point mutations as well as small insertion or deletion mutations. This technology is amenable to automation and is suitable for immediate utilization for high-throughput genetic diagnostics in clinical and research laboratories.