Lethal activity of miconazole in Neisseria gonorrhoeae grown in pure and mixed cultures

Abstract Low concentrations (e.g. 2 × 10⁻⁶ M) of an imidazole derivative anti-fungal agent, miconazole, were lethal for the Gram-negative, facultative aerobic pathogen Neisseria gonorrhoeae grown either alone or in mixed culture with the yeast Candida albicans . Electron microscopic observation of Neisseria cells exposed to miconazole showed the presence of blebs in the outer wall and areas of separation between the wall and the cytoplasmic membrane. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of cell lysates did not reveal differences in major outer membrane proteins between the treated and the untreated cells of any one strain. Imidazole derivatives are frequently used in the treatment of candidiasis. Our in vitro results show that low concentrations of one of them, miconazole, can be bactericidal for N. gonorrhoeae , a bacterium that can colonise sites of the human body where Candida is often found.     

Evidence for the presence of Calbindin-D 28K (CaBP-28K) in the tibial growth cartilages of rats

Summary The distribution of the vitamin-D dependent calcium-binding protein (Calbindin-D 28K) (CaBP-28K) in the tibial growth plate cartilage of the rat has been studied immunohistochemically using an antibody raised against rat renal CaBP-28K. The protein was detected mainly in the nuclei of chondrocytes and occasionally in the juxta-nuclear cytoplasm. The distribution was not uniform throughout the growth plate, but concentrated in the proliferatively active chondrocytes of the resting and proliferative zones. These findings raise the possibility that CaBP-28K may be involved in the mitotic activity of the chondrocytes, acting as a regulator of the proliferative process, perhaps via intranuclear calcium.     

The response of the skin of swine to increasing single exposures of 250-KVP X-rays

When the skin of the shoulder ("A" field) and lower back ("C" field) is irradiated through 10-cm-diameter fields with 250-kVp x-rays, having a HVL of 0.87 mm copper, a dose range is reached between approximately 1600 rads and 3000 rads in which a moist reaction is or is not formed. If a moist reaction is formed, it either heals completely, partially, or not at all. The evolution, time course, and dose dependence of the moist reaction that occurs following irradiation has been determined. The moist reaction is found at 17.5 +/- 0.6 days in the "A" field, and 20.8 +/-0.8 days in the "C" field. The reaction evolves to involve from 5 % to 100% of the field by 24.9 +/- 0.5 days in the "A" field and by 28.5 +/- 1.0 days in the "C" field. Healing is complete by 36.0 +/-1.0 days in the "A" field and by 38.0 +/- 1.3 days in the "C" field. The area of the field involved with a moist reaction at the time of maximal involvement is dose-dependent. The area of the field involved with a moist reaction at the time of complete healing is also dose-dependent. The dose at which 50 % of the fields were not healed was 2273 +/-103 rads in the "A" field, 2578 +/-141 rads in the "C" fields, and 2437 +/- 89 rads in the "A" and "C" fields. The values in the "C" field are significantly different from those in the "A" field except for the dose at which 50 % of the fields were not healed and the time at which the field was maximally healed.     

Infection in Mouse Peritoneal Cavity with a Pyrimidine-requiring Mutant and Naturally Occurring Staphylococcus aureus Strains

The lethal activity of a thymineless mutant of Staphylococcus aureus Wood 46 strain has been compared with that of three naturally occurring strains: parent Wood 46, Smith, and coagulase-negative SA-13. The thymineless mutant and the parent Wood 46 strain showed a sharp decline in culturable units from the peritoneal cavity in the first 4 hr after their injection. After 6 hr, that is, 2 hr before the mice began to die, the number of culturable units of the thymineless mutant was still declining, whereas that of the parent strain increased; for both strains, the number of units was still lower than that of the inoculum. Although the thymineless mutant, unlike the parent strain, was apparently unable to multiply in mouse peritoneal cavity, it killed mice at a similar rate. The highly virulent Smith strain known to multiply rapidly and the avirulent coagulase-negative SA-13 strain were used as additional controls. Under our experimental conditions, death of mice after the injection of the thymineless mutant in the peritoneal cavity did not seem to be due to bacterial multiplication but to toxicity, death being delayed by antitoxin. The pyrimidine-requiring auxotroph we used could be better material than killed bacteria to study some aspects of the lethal activity of S. aureus.     

Confirmation and refinement of the genetic localization of the Coffin-Lowry syndrome locus in Xp22.1-p22.2

The Coffin-Lowry syndrome (CLS) is an X-linked inherited disease of unknown pathogenesis characterized by severe mental retardation, typical facial and digital anomalies, and progressive skeletal deformations. Our previous linkage analysis, based on four pedigrees with the disease, suggested a localization for the CLS locus in Xp22.1-p22.2, with the most likely position between the marker loci DXS41 and DXS43. We have now extended the study to 16 families by using seven RFLP marker loci spanning the Xp22.1-p22.2 region. Linkage has been established with five markers from this part of the X chromosome: DXS274 (lod score [Z] (theta) = 3.53 at theta = .08), DXS43 (Z(theta) = 3.16 at theta = .08), DXS197 (Z(theta) = 3.03 at theta = .05), DXS41 (Z(theta) = 2.89 at theta = .08), and DXS207 (Z(theta) = 2.73 at theta = .13). A multipoint linkage analysis further placed, with a maximum multipoint Z of 7.30, the mutation-causing CLS within a 7-cM interval defined by the cluster of tightly linked markers (DXS207-DXS43-DXS197) on the distal side and by DXS274 on the proximal side. Thus, these further linkage data confirm and refine the map location for the gene responsible for CLS in Xp22.1-p22.2. As no linkage heterogeneity was detected, this validates the use of the Xp22.1-p22.2 markers for carrier detection and prenatal diagnosis in CLS families.     

Genetic analysis of two tomato mutants affected in the regulation of iron metabolism

Iron is one of the most important micronutrients for plants. Like other organisms, plants have developed active mechanisms for the acquisition of sufficient iron from the soil. Nevertheless, very little is known about the genetic mechanisms that control the active uptake. In tomato, two spontaneously derived mutants are available, which are defective in key steps that control this process. The recessive mutationchloronerva (chln) affects a gene which controls the synthesis of the non-protein amino acid nicotianamine (NA), a key component in the iron physiology of plants. The root system of the recessive mutantfer is unable to induce any of the characteristic responses to iron deficiency and iron uptake is thus completely blocked. We present a characterization of the double mutant, showing that thefer gene is epistatic over thechln gene and thus very likely to be one of the major genetic elements controlling iron physiology in tomato. In order to gain access to these two genes at the molecular level, both mutants were precisely mapped onto the high density RFLP map of tomato. Thechln gene is located on chromosome 1 and thefer gene is on chromosome 6 of tomato. Using this high-resolution map, a chromosome walk has been started to isolate thefer gene by map-based cloning. The isolation of thefer gene will provide new insights into the molecular mechanisms of iron uptake control in plants.