微生物学技术

Bacterial attachment to host receptors is a prerequisite for colonization of epithelial cell surfaces, in particular, continuously renewing mucosal surfaces, such as the gastrointestinal tract. Microbes express adhesion molecules for interactions with eukaryotic cell su ...

The outer membranes of Gram-negative bacteria represent selective, permeability barriers to environmental molecules. This function is accomplished in two ways. First, outer membranes exclude many larger hydrophilic molecules, including enzymes and other proteins, and most ...

Until the discovery of Helicobacter pylori in 1982, the normal human stomach was generally considered to be sterile, or transiently populated by oropharyngeal bacteria carried there by peristalsis. However, we now know that from one-third to one-half of the human population carries H. pyl ...

Despite its clinical significance, relatively little is known about the components of Helicobacter pylori that allow it to colonize, persist, and elicit an inflammatory response within the host. Bacterial surface components frequently influence colonization and persistence ...

The inability of conventional gel electrophoresis to separate DNA molecules exceeding 50 kb in size led to the development of pulsed-field gel electrophoresis (PFGE) by Schwartz et al, (1)in 1982. He introduced the concept of applying two alternating electric fields (i.e., pulsed-field) to ...

Ever since the realization that Helicobacter pylori was intimately associated with the development of gastritis and peptic ulcer disease in humans, there has been a need for a simple animal model in which modes of pathogenicity, transmission, immunization, and chemotherapeutic inte ...

The selectivity of Helicobacter pylori for the antral mucosa of the stomach and gastric metaplasia in the duodenum combined with the inaccessibility of those sites has hindered the investigation of this infection. Consequently, the study of the epidemiology and treatment of H. pylori has ...

Detection of Helicobacter pylori in specimens obtained by endoscopy requires the gastroenterologist to select suitable patients for endoscopy, and to take an adequate number of biopsy specimens; there must also be correct cleaning of the biopsy forceps.

A number of methods are currently available for the detection of Helicobacter pylori, including serology, culture, histology, and isotope breath tests. All have relative advantages and disadvantages of sensitivity, specificity, convenience, expense, and immediacy. The polyme ...

Helicobacter pylori is a curved Gram-negative bacillus that infects the human gastric mucosa. Most methods used to diagnose H. pylori require the collection of gastric samples by biopsy during gastroduodenoscopy. A positive culture or visualization of the organism by histologic exa ...

A crucial step in the baculovirus expression system technique is the selection of recombinant viruses. In most cases positive clones, i.e., recombinant viruses, are detected via the presence of foreign DNA, or by exploiting the phenotypic differences between wild-type viral plaques, wh ...

Protocols for the isolation of recombinant baculoviruses and their use for foreign gene expression in insect cells have been described in detail in the preceding chapters (also see refs. 1–5). Generally, this approach involves the replacement of viral DNA sequences encoding the polyhed ...

Stirred-tank fermentors were originally designed to perform microbial cultures (1). When the need arose for adequate, posttranslationally modified proteins, molecular biologists and bioprocess engineers turned to mammalian and insect cell culture using these fermentors ...

The recombinant baculovirus expression system, developed in the laboratories of Summers (1) and Miller (2), has been widely used for the production of heterologous proteins (3, 4). In this system, the gene to be expressed is cloned into a plasmid transfer vector, downstream of a strong baculovir ...

Baculoviruses have been isolated from a wide range of invertebrates. Their development as pest control agents spans over 40 years, although records of their discovery and use date from considerably earlier (1). The baculoviruses from Lepidoptera (butterflies and moths), Hymenoptera ...

A large number of eukaryotic proteins have been successfully overproduced in insect cells infected with a natural pathogen, a baculovirus, in which foreign gene coding sequences were placed under the control of the viral polyhedrin gene promoter. This expression system is effective be ...

Baculovirus expression vector systems based on the nuclear polyhedrosis viruses of Autographa californica (AcNPV) and Bombyx mori (BmNPV) are in wide use (1). Our laboratory originally designed the BmNPV system with the objective of using the silkworm, B. mori, as an in vivo host (1a, 2). The silkw ...

The acquired immune deficiency syndrome (AIDS) is caused by human immunodeficiency virus type 1 or 2 (HIV-l or HIV-2). The disease is characterized by a high susceptibility to opportunistic infections or to malignant diseases, such as Kaposi’s sarcoma. The major immunologic abnormality is ...

Baculovirus vectors have been developed for the expression of foreign genes in insect cells. Protein yields are often significantly higher than in bacterial, yeast, or vertebrate expression systems (12). It was therefore of interest to test the capacity of this system to direct the complex a ...

The baculovirus expression system represents an elegant means whereby high-level expression of foreign genes can be achieved using eukaryotic insect cells (1,2). Viruses from the Baculoviridae subfamily of insect viruses, usually Autographa californica nuclear polyhedro ...