Laser therapy of Barrett''s mucosa

Midden and Dahl, in a recent paper, have presented important data on the inactivation of bacteria by singlet oxygen. In analyzing the data, use was made of a theory published earlier by the present author. The purpose of this paper is to point out that theory and experiment can be brought into better agreement by assuming that the interaction of singlet oxygen with the bacteria takes place in an essentially lipid environment rather than aqueous.     

Regulation of the raffinose permease of Escherichia coli by the glucose-specific enzyme IIA of the phosphoenolpyruvate:sugar phosphotransferase system

In enteric bacteria, chromosomally encoded permeases specific for lactose, maltose, and melibiose are allosterically regulated by the glucose-specific enzyme IIA of the phosphotransferase system. We here demonstrate that the plasmid-encoded raffinose permease of enteric bacteria is similarly subject to this type of inhibition.     

Adaptation of thermafil components to canal walls

In summer 1991 an outbreak of a Salmonella enteritidis epidemic involving about 600 cases of gastroenteritis occurred at one of the leading pharmaceutical companies in southwestern Germany. The main source was a cold fruit soup, in addition Salmonella were isolated from meat strips and a curd cheese which were used for a salad dressing. A total of 2300 contaminated food portions were served resulting in an attack rate of about 25%. The possible origin could have been an asymptomatic Salmonella-positive member of the kitchen personnel who was the only one who was involved with the preparation of all the incriminated foods. A further spread of the epidemic and especially the possible contamination of pharmaceuticals was avoided by the timely and adequate reaction of the company's occupational medical service. This case exemplifies how classical crisis management, "increased initiative on one's own for prevention of infections in all areas of food processing" (Steuer) and finally the cooperation of the company with different institutions of the public health authorities contribute to the control of such a catastrophic scenario.     

Problems with India ink skin markings

India ink skin markings allow consistently reproducible radiation field setups. The authors report a case in which a facial tattoo was applied with an injection, resulting in permanent "black eyes." The vaccination technique has not been associated with this complication.     

Imported measles. A potential control problem

From Dec 23, 1978, through Jan 31, 1979, an outbreak of five laboratory-confirmed cases and four clinical cases of measles occurred in a Vietnamese refugee population living in a single housing complex in Albuquerque, NM. The index cases were in two refugee siblings in whom measles was incubating on arrival in the United States. Despite spread through three subsequent generations of disease transmission within the Vietnamese population, there was no additional spread into the general Albuquerque population. Responsible factors included the age distribution of susceptible persons, the social isolation of the refugee population, and the physical structure of the housing complex. There is a need to identify the problem of imported measles in "ethnic islands" in need of vaccination.     

Diazepam-ketamine anaesthesia for open heart surgery a "micro-mini" drip administration technique

Two hundred open-heart cases were anaesthetized with a diazepam-ketamine combination. The results were excellent. A "Micro-Mini" drip technique insured low, even, but adequate dose levels of ketamine and less drug was used. Induction and maintenance are simple and smooth. Effects on the cardiovascular system and respiratory system are minimal. The margin of safety is wide and 100% oxygen can be used whenever needed.     

Modeling of bone conduction of sound in the human head using hp-finite elements: Code design and verification

We focus on the development of a reliable numerical model for investigating the bone-conduction of sound in the human head. The main challenge of the problem is the lack of fundamental knowledge regarding the transmission of acoustic energy through non-airborne pathways to the cochlea. A fully coupled model based on the acoustic/elastic interaction problem with a detailed resolution of the cochlea region and its interface with the skull and the air pathways, should provide an insight into this fundamental, long standing research problem. To this aim we have developed a 3D hp-finite element code that supports elements of all shapes (tetrahedra, prisms and pyramids) to better capture the geometrical features of the head. We have tested the code on a multilayered sphere and employed it to solve an idealized model of head. In the future we hope to attack a model with a more realistic geometry.     

Cross-cultural comparison of organizational media evaluation and choice

Managers working in four countries reported the richness of five media, equivocality of 11 situations, preferred media for each situation, and cultural values. The richness and equivocality measures were reliable and unidimensional. Face-to-face was ranked as most, and business memos least, rich. Only E-mail and telephone preferences were significantly correlated with richness. Media preferences for face-to-face and telephone for each situation were highly correlated with the situations' equivocality. Respondents from collectivist countries rated the telephone as less rich, and the business memo as richer, than did respondents from individualist countries.     

Ligand interactions with the acetylcholine receptor from Torpedo californica. Extensions of the allosteric model for cooperativity to half-of-site activity

The solubilized acetylcholine receptor from Torpedo californica showed positive cooperativity in acetylcholine binding with a dissociation constant of 1.2 X 10(-8) M. Blockade of acetylcholine binding by nicotine was competitive; blockade by d-tubocurarine appeared to result from an allosteric interaction that altered half of the acetylcholine binding sites to a lower affinity form; decamethonium blockade displayed properties of competitive and allosteric inhibition suggesting less specificity for decamethonium binding than seen with either nicotine or d-tubocurarine. The d-tubocurarine inhibition data were evaluated by several possible models involving either differential competitive inhibition or allosteric inhibiton. The data were best described by the allosteric model.