Tuberculosis infection of the breast mistaken for granulomatous mastitis: a case report

BACKGROUND

Tuberculosis of the breast is an uncommon disease with non-specific clinical, radiological and histological findings. Misdiagnosis is common as biopsy specimens are pauci-bacillary and investigations such as microscopy and culture are frequently negative.

CASE PRESENTATION

We report a case of a breast abscess in a 34-year old Bangladeshi woman attributed to tuberculosis infection. Equivocal histology, negative Ziehl-Neelsen stain and culture for acid-fast bacilli resulted in the abscess initially being diagnosed as granulomatous mastitis and treated accordingly. However failure to respond to therapy raised suspicion of culture negative breast tuberculosis. Treatment with standard antituberculosis drugs was associated with complete resolution of the breast abscess.

CONCLUSION

This case highlights the difficulty in differentiating culture negative tuberculosis from granulomatous mastitis and the importance of a high index of clinical suspicion.

The interaction of ancrod with human platelets

Ancrod, a serine protease purified from the venom of Agkistrodon rhodostoma, has been used as a therapeutic anticoagulant for a number of indications, including replacement of heparin in patients with heparin-induced thrombocytopenia. Ancrod has similar fibrinolytic activity to thrombin, but ancrod specifically cleaves only the alpha chain of fibrinogen, producing the characteristic fibrinopeptides A, AP and AY. Because ancrod has been used in patients with heparin-induced thrombocytopenia, it is important to ensure that ancrod does not directly affect the platelets and potentially increase the hemostatic effect. The effect of ancrod on platelets has not been well established, and there is not agreement in published studies. Additionally, some of the studies are over 15 years old and pre-date sensitive assays such as glycoprotein analysis. For these reasons, we investigated the interaction of ancrod with human platelets using direct and indirect, functional and biochemical techniques. Incubation of platelets with ancrod alone did not induce platelet aggregation or the release of dense-granule contents. Pre-incubation of platelets with ancrod did not augment or inhibit the maximal aggregation achieved with thrombin, nor did it affect the amount of serotonin release from dense granules caused by activation by thrombin. Studies of ancrod-treated platelets using monoclonal antibody-mediated radioimmunoprecipitation demonstrated that high concentrations of ancrod did not cause measurable cleavage of either the glycoproteins Ib-IX or IIb-IIIa. Incubation of radiolabeled platelets with ancrod-treated plasma also had no effect on the platelet glycoproteins, indicating that ancrod does not indirectly affect the major surface receptors. Direct binding studies using radiolabeled ancrod did not demonstrate specific binding to the platelet surface. Together these studies indicate that ancrod does not directly affect nor bind to platelets in vitro. The hypo-coagulant state and subsequent platelet function defect resulting from the use of ancrod appears to be limited to the removal of fibrinogen from the circulation.

Second-harmonic generation optical activity of a polypeptide alpha-helix at the air/water interface

Quantitative measurements of second-harmonic generation optical activity (SHG-OA) have been performed for alpha-helical polypeptides poly-(gamma-benzyl-L-glutamate) and poly-(gamma-ethyl-L-glutamate) adsorbed at the airwater interface, with the fundamental frequency variant Planck's over 2piomega = 2.96 eV (lambda = 417 nm). The chiral component of the nonlinear susceptibility chi(XYZ) ((2)) is small for both polymers, being comparable in magnitude with the susceptibility chi(XXZ) ((2)) of the clean airwater interface. The microscopic origin of the nonlinear response has been investigated by using semiempirical ZINDOS calculations in conjunction with standard time-dependent perturbation theory to evaluate the molecular hyperpolarizability tensor of a model alpha-helix composed of glycine residues. Calculated nonlinear susceptibilities (per monomer unit) are in good agreement with experimental measurements for both the chiral and achiral response. The computational results indicate that charge transfer transitions of the alpha-helix have a large influence on the achiral components of the hyperpolarizability tensor, and produce characteristic features in the response under suitable experimental conditions. The dominant origin of SHG-OA for the model alpha-helix is a structural effect due to the tilt of the plane of each amide group of the helix relative to the helical axis. SHG-OA is associated with the orientational distribution of isolated, achiral chromophores, and is present in the absence of electronic coupling between the amide subunits of the polypeptide alpha-helix.

Application of a serum-free medium for the growth of Vero cells and the production of reovirus

Two strains of reovirus (serotype 1 Lang/TIL and serotype 3 Dearing/T3D) were propagated in Vero cells grown in stationary or agitated cultures in a serum-free medium, M-VSFM. Solid microcarriers (Cytodex-1) were used to support cell growth in agitated cultures with a normal doubling time of 25 h. Cell yields of 1 x 10(6) cells/mL were obtained from an inoculum of 2 x 10(5) cells/mL in 4 days in microcarrier cultures. The growth profile and cell yield was not significantly different from serum-supplemented cultures. The virus titer increased by 3-4 orders of magnitude over a culture period of 150 h. The maximum virus titer in stationary cultures reached >1 x 10(9) pfu/mL for both strains of reovirus in M-VSFM. M-VSFM also supported high viral yields in microcarrier cultures. Both the specific productivity and final viral yield was higher in M-VSFM than serum-supplemented cultures. The high viral productivity suggests that this is a suitable system for the production of reovirus as an oncolytic agent for human therapeutic use.

Measles vaccine: a 27-year follow-up

In 1964, the Medical Research Council undertook a trial of measles vaccine in over 36,000 United Kingdom children; 9577 of whom received live vaccine, 10,625 received inactivated followed by live vaccines, and 16,328 acted as unvaccinated controls. Participants in this study have been followed to determine the long term protection from measles vaccine and follow-up data were available on 4194, 4638 and 274 respectively. During the 5-year period 1986-90, the protective efficacy of live measles vaccine has remained high at 87%, but the 95% confidence interval was wide (-43 to 99%) due to the small numbers of cases. Between 1976 and 1990, however, the overall efficacy of the live vaccine was 92% (95% confidence interval 86 to 95%) and there was no evidence of a decline in efficacy (P = 0.13) over the 15-year period. This study suggests that the protection from live measles vaccine persists for up to 27 years after vaccination, and that no change in the current United Kingdom measles immunization policy should be made on the grounds of waning immunity.

Characterization of cooperative conformational transitions by Fourier transform infrared spectroscopy: application to phospholipid binary mixtures

Temperature-induced cooperative conformational transitions in biopolymers may be examined in aqueous solution by the use of Fourier transform infrared spectroscopy. The transition is described in terms of a two-state model with a fractional population parameter (which describes the degree of transition at various values intermediate between the two limiting cases) that can be generated by a least-squares technique. This procedure allows for calculation of a conformational index without assuming a linear dependence of the infrared parameter on the extent of transition. Calculations based on the Zimm–Bragg theory of cooperative conformational transitions allow thermodynamic quantities to be derived using the conformational index in conjunction with calorimetric measurements.The method is illustrated with data from the gel/liquid-crystalline phase transitions of binary phospholipid vesicles where the use of isotopic substitution allows the conformation of each component of the binary mixture to be independently monitored. The data suggest the coexistence of well-defined structural domains of phospholipid as well as the preferential clustering of one of the lipid components at the interface between the two phases.