Ga-67 used to localize the tumor bed for radiation therapy after lumpectomy

The authors present a new method to locate the tumor bed after lumpectomy. The method relies on accumulation of Ga-67 at the surgical site. This technique was useful in identifying the tumor bed in six candidates for breast conserving surgery and radiation therapy. This method may be applicable in other soft tissue malignancies that require postoperative radiation.     

Design and synthesis of amphipathic antimicrobial peptides

A large proportion of antimicrobial peptides share a common structural feature that is critical to their antimicrobial activity, i.e. amphipathic alpha-helices. The amphipathy of a polypeptide chain can be quantitated through the value of the hydrophobic moment. Generally, antimicrobial peptides are characterized by high hydrophobic moment and low hydrophobicity values. Using these criteria we have identified two short segments that possess hydrophobic moment properties associated with known antimicrobial peptides. Using in vitro assays the segment derived from the protein perforin displays no antifungal or antibacterial activity and, while showing no alpha-helicity in buffer or liposomes, exhibits a modest degree of alpha-helical structure in the presence of the alpha-helical inducer, 2,2,2-trifluoroethanol. However, rational modifications result in a derivative which assumes an alpha-helical conformation in the presence of liposomes, exhibits potent antifungal activity against plant fungal pathogens, has significant antibacterial activity, effects leakage of a fluorescent dye from acidic liposomes and is devoid of hemolytic activity. Results are also presented for a segment derived from the human immunodeficiency virus envelope protein. We suggest that the identification of putative amphipathic structures in proteins may provide a useful starting strategy in the design and synthesis of antimicrobial peptides.     

Selective aortic arch perfusion using serial infusions of perflubron emulsion

With the aim of developing foetal gene therapy for cystic fibrosis, we have investigated the possibility of gene targeting to the mouse foetus with two different viral vector systems and at different times of gestation. We report here that recombinant retrovirus producing cells administered into the intra-amniotic cavity of mid- to late-gestation mouse MF1 foetuses survive in the amniotic fluid and are able to engraft to a certain extent in foetal tissues. By production of infectious virus they mediate transduction and beta-galactosidase transgene expression in neighbouring foetal tissues 24 to 72 h following injection. Retrovirus producer cells could, therefore, become a means to overcome the limitations of low retroviral titre, for in vivo foetal gene transfer. To investigate the developmental stage at which transduction of the airways and enteral systems can be obtained we also administered a highly infective first generation adenoviral vector (AdRSV beta gal) into the amniotic cavity of foetal mice between 13 to 16 days post coitus, beta-galactosidase activity was detected between 24 to 120 h after injection. The highest levels of transgene expression were generally observed between 48 to 72 h following injection of the adenoviral vector. We demonstrate that infection of the pulmonary airways is dependent on the developmental stage of the foetus and can be achieved on the 15th day of gestation.     

Disinhibition of return: unnecessary and unlikely

Recently, from data obtained with a temporal order judgment (TOJ) task, Gibson and Egeth (1994) concluded that inhibition of return (IOR; a response time effect that reveals slower responding to targets at previously cued versus uncued locations) reflects impaired perceptual processing. By replotting their data, we demonstrate that the perception of temporal order is influenced only by the facilitatory effect of a cue at short stimulus onset asynchronies (SOAs) and is unaffected by IOR at long SOAs. The target paper proposed that, when extra stimuli are presented at task-relevant locations (i.e., in the TOJ task), IOR is prevented by a hypothetical process that is known as disinhibition of return (DOR). We argue that the assumptions that IOR affects perceptual processing and that DOR exists are unnecessary, as a more parsimonious response-based interpretation of IOR is consistent with their data. Further, we summarize recent results and present new data that demonstrate that DOR is unlikely.     

Successful delayed thrombolytic therapy in a patient with massive pulmonary embolism

Pica is the persistent, culturally and developmentally inappropriate ingestion of non-nutritive substances (DSM-IV). AB is a 75-year-old lady with a 40-year history of schizophrenia and a 20-year history of pica who, at emergency laparotomy, had 175.32 Pounds of loose change in her stomach. Although pica has been reported to coexist with schizophrenia, she had had no positive symptoms of schizophrenia for at least 20 years. She has CT evidence of fronto-tempotal atrophy most marked on the left in the temporal lobe and on the right in the frontal lobe. Pica has been found to be related to cognitive deficits and hyperoral behaviour to temporal lesions. Neuropsychological testing reveals deficits closely related to these changes.