Needle placement accuracy during stereotactic localization mammography.

AIM: To derive a mathematical model to describe the relationship between lesion position in the breast and measurements derived from the stereoradiographs to enable more accurate sampling of a lesion during stereotactic mammographic needle placement. MATERIALS AND METHODS: The affect that registration errors have on the accuracy of needle placement when identifying the lesion on the stereoradiographs was investigated using the mathematical model. RESULTS: The focus-to-film distance of the x-ray tube and the horizontal distance of the lesion from the centre of rotation have little effect on error. Registration errors for lesions lying at a greater perpendicular distance in the breast from the centre of rotation produce smaller localization errors when compared with lesions sited closer. Lesion registration errors during marking of the stereoradiographs are exacerbated by decreasing the angle of x-ray tube swing. CONCLUSIONS: When problems are encountered in making an accurate registration of the lesion on the stereoradiographs, consider the following error reducing strategies: (1) employ an approach that places the lesion the maximum distance away from the film cassette; (2) avoid reducing the angle of tube swing; and (3) consider sampling superficial and deep to, as well as at, the location indicated. The possibility of erroneous tissue sampling should be borne in mind when reviewing the pathology report.

Glycoprotein emulsifiers from two marine Halomonas species: chemical and physical characterization.

AIMS: To partially purify and characterize bioemulsifiers produced by two new marine Halomonas species, TG39 and TG67, and to compare their emulsifying activities with those of commercial emulsifiers. METHODS AND RESULTS: The production of emulsifiers HE39 and HE67 was achieved from glucose-supplemented marine broth, and recovered by cell removal, concentration by ultrafiltration, precipitation with salt and ethanol, and lyophilization. Purification and chemical analysis revealed both emulsifiers to be glycoproteins of high molecular weight with a notably high content of protein and uronic acids. Physical characterization showed both glycoproteins to effectively emulsify a wide range of food oils under both neutral and acidic pH conditions and withstand acid and high temperature treatment. CONCLUSIONS: The emulsifying activities of these two new glycoprotein emulsifiers were comparable and, under certain conditions, superior to those produced by commercial emulsifiers tested (xanthan gum, gum arabic and lecithin). They show the highest reported emulsifying activities derived from a Halomonas species. SIGNIFICANCE AND IMPACT OF THE STUDY: These strains, and the emulsifiers produced, appear to be promising candidates for further development in applications requiring emulsifiers that are natural and compatible to the existing commercial emulsifiers.

Nodal rhythm and bradycardia during inhalation induction with sevoflurane in infants: a comparison of incremental and high-concentration techniques.

We studied heart rate and rhythm changes during sevoflurane inhalation induction in 60 healthy, unpremedicated infants. Patients were allocated randomly to receive an incremental (2% sevoflurane, increased every four to six breaths by 2% increments, to 8%) or high-concentration induction technique (8% sevoflurane from the outset). The ECG was recorded for 330 s (30 s pre- and 300 s postinduction) using a mini-Holter device (Recollect Dual Channel, Hertford Medical) and later analysed by an independent observer. Twelve patients developed nodal rhythm (six in each group), but no other dysrhythmias were recorded. The onset of nodal rhythm was associated with bradycardia (< 80 bpm) in seven out of 12 cases, and occurred significantly earlier in the high-concentration group (median 123 (range 99-139) s versus 164 (127-138) s). Its duration was similar in both groups (62 (2-84) s versus 90 (20-167) s). These findings highlight the importance of using continuous ECG analysis when studying volatile anaesthetic agents in young children.

Membrane topology of the Bacillus subtilis pro-sigma(K) processing complex.

Activation of the final sporulation-specific transcription factor, sigma(K), is regulated by a signal emanating from the forespore which interacts with the pro-sigma(K) processing complex, comprising SpoIVFA, BofA, and the pro-sigma(K) processing protease, SpoIVFB. Mature sigma(K) then directs late gene expression in the parental compartment of the developing sporangial cell. The nature of this complex and how it is activated to process pro-sigma(K) are not understood. All three proteins are predicted to be integral membrane proteins. Here, we have analyzed the membrane topology of SpoIVFA and SpoIVFB by constructing chimeric forms of spoIVFA and spoIVFB with the complementary reporters phoA and lacZ and analyzing activity in Escherichia coli. SpoIVFA was found to have a single transmembrane-spanning domain, while SpoIVFB was shown to have six transmembrane-spanning domains (6-transmembrane configuration). Further, SpoIVFA is required to stabilize SpoIVFB in the membrane. SpoIVFB was shown to have a 4-transmembrane configuration when expressed on its own but was found to have a 6-transmembrane configuration when coexpressed with SpoIVFA, while BofA had a positive effect on the assembly of both SpoIVFA and SpoIVFB. The single transmembrane domain of SpoIVFA (approximately residues 73 to 90) was shown to be the principle determinant in stabilizing the 6-transmembrane configuration of SpoIVFB. Although the bofB8 allele, which uncouples the sigma(K) checkpoint, did not appear to promote a conformational change from a 6- to 4-transmembrane configuration of SpoIVFB (apparently ruling out a profound conformational change as the mechanism of activating SpoIVFB proteolytic activity), instability of SpoIVFB may be an important factor in SpoIVFB-mediated processing of pro-sigma(K).

Characterization of two Bacillus probiotics.

Bacillus subtilis is currently used as an oral probiotic. We examined two commercial B. subtilis probiotic preparations, Enterogermina and Biosubtyl. Surprisingly, physiological and genetic characterization of the bacteria contained in each of these preparations has shown that neither contains B. subtilis.

Hoarseness after tracheal intubation.

The reported incidence of hoarseness following short-term tracheal intubation varies widely. It has been reported as being permanent in 3%. This suggests that an enormous problem exists considering the numbers of patients intubated daily in the United Kingdom. A prospective study of 235 adult patients undergoing general anaesthesia in a district general hospital included 167 patients whose tracheas were intubated. Of these 167, 54 (32%) complained of hoarseness postoperatively. All but five returned to normal within 7 days. The others were hoarse for 9, 10, 12, 54 and 99 days. Those who were hoarse for 54 and 99 days had vocal cord granulomata. Regression analyses showed that certain patient and anaesthetic factors had a significant effect on the hoarseness. This study confirms a low incidence of prolonged or permanent hoarseness following short-term tracheal intubation.

Blue field entoptoscopy in the preoperative evaluation of vitrectomy candidates.

Twenty-four patients with vitreous hemorrhage scheduled for pars plana vitrectomy were evaluated with the blue field entoptoscope. Correlation of pre- and postoperative findings in patients with and without macular pathology was highly irregular, apparently due to mechanical obstruction of light transmission by the vitreous hemorrhage. Blue field entoptoscopy is therefore not recommended as a tool in the preoperative evaluation of vitrectomy patients.

Parvovirus infection in a family associated with aplastic crisis in an affected sibling pair with hereditary spherocytosis.

There have been many reports of aplastic crisis preceded by a febrile illness in hereditary haemolytic anaemias. Recent research has shown that the human parvovirus may be a causative agent. We report on an adult sibling pair with hereditary spherocytosis who presented in aplastic crisis after a febrile illness. Both had evidence of recent parvovirus infection, shown by the presence of IgM class specific antibody in their sera. The children of one of the sibling pair, one of whom has hereditary spherocytosis but no chronic haemolysis, showed similar evidence of acute parvovirus infection.

Chemistry, geochronology, and petrogenesis of lunar sample 15555.

Lunar sample 15555 is a mare type basalt generally similar in chemical composition to the Apollo 12 basalts. Sample 15555 is older than any Apollo 12 basalt but younger than the Apollo 14 basalts analyzed thus far.