Inherited resistance

The insect s choice of food may be governed to a considerable extent, as ours is, by attractants and repellents. In many instances, the actual insecticidal action of plant extractives may be due primarily to an artificially high level of application, while, in fact, the parent plants are only repellent in the field. This repellency may appear to be resistance on the part of the plant, and the chemistry of such resistance factors has begun to receive much-needed attention. For example, Smissman and his coworkers have examined the chemical basis for the inherited resistance of some strains of corn to attack by the European corn borer. 6-Methoxybenzoxazolinone (X) was isolated (2, SO) and shown to be one of the principal resistance factors, and a number of synthetic analogs were found to... 

The mechanism of inherited resistance proceeds through R-plasmids, which, like chromosomes, are also collections of DNA representing genes capable of coding and inducing the production of new proteins in the bacterial cell. In this fashion, the plasmid can provide the cell with a greater chance of survival and propagation. 

Inherited resistance in bacteria is accepted as the most important type from the standpoint of the community and the environment. Studies of isolated microorganisms of animal and human origin have demonstrated that plasmids from both sorts of isolates were practically identical. In terms of the dissemination of resistance determinants of R-plasmids, one must regard the problem as involving both humans and animals as vectors. Presence of a large reservoir of antibiotic-resistant organisms in animals has been demonstrated in the United States. 

Other causes of low serum calcium are less common. Hypoparathyroidism is due most commonly to parathyroid gland destruction during neck surgery (90%), and less commonly is idiopathic. Pseudohypoparathyroidism is biochemically similar to hypoparathyroidism however, these patients have inherited resistance to PTH and elevated concentrations of PTH. The molecular basis for the most common form, pseudohypoparathyroidism type I (Albright s hereditary osteodystrophy), is a reduction in guanine nucleotide regulatory complex. Ns, in the adenylate cyclase complex. 

B. Zoller, B. Dahlback. Linkage between inherited resistance to activated protein C and factor V gene mutation in venous thrombosis. Lancet. 1994, 343, 1536-1538. 

In recent years, resistance or tolerance to herbicide injury has become a very important objective for cultivar development. Currently, tolerance to glyphosate is present in most cultivars in the United States, Argentina, and Brazil. This trait was introduced via transformation and is simply inherited. Resistance or tolerance to other herbicides including metribuzin, dicamba, glufosinate, and 2,4D have been reported and in some cases tolerant versions of cultivars released. The resistance or tolerance is... 

A.Gecse, S. Karady and G.B. West, Inherited Resistance of Rats to Traumatic and Tourniquet Shock, J. Physiol., Lond. 177, 9P (1964). 

In about 30-40% of patients with suspected inherited thrombophilia the PC-pathway is disturbed by a mutation ofFV (FV-Leiden). TheFV-Leiden mutation affects one of the APC cleavage sites within the FV molecule. As a consequence, mutated FVa becomes resistant to rapid APC inactivation (APC resistance). About 4-7% of the middle European population cany this polymorphism of FV. Inborn deficiencies of Protein-S or Protein-C are much less frequent (< < 1% and 0.2-0.4%, respectively). 

Mutations in GK (Hx IV) causes maturity-onset diabetes of the young (MOD Y), a form of non-insulin-dependent diabetes mellitus (NIDDM) characterized by onset before 25 years of age and an autosomal dominant inheritance (PI 2). This suggests that the mutations in other forms of Hx may also contribute to the development of NIDDM. Among them, Hx II is a particularly attractive candidate, although this isozyme is not expressed in red blood cells. Hx II has been analyzed extensively in the muscle of prediabetic insulin-resistant individuals. But studies have shown that Hx II mutation alone is unlikely to have a significant role in the development of peripheral insulin resistance and NIDDM (L6). 

Cook, R. and York, P.A. (1982) Resistance of cereals to Heterodera avenaer. methods of investigation, sources, and inheritance of resistance. OEPP/EPPO Bulletin 12, 423-434. 

Triantaphyllou, A.C. (1975) Genetic structure of races of Heterodera glycines and inheritance of ability to reproduce on resistant soybean. Journal of Nematology 7, 356. 

Islam, A.K.M.R. and S.B. Powles. 1988. Inheritance of resistance to paraquat in barley grass Hordeum glaucum Steud. Weed Res. 28 393-397. 

It is well known, for example, that about 5 per cent of the people who become infected with typhoid germs become typhoid carriers and continue indefinitely to harbor an active colony (harmless to them) of typhoid bacilli in their intestinal tracts. There is abundant evidence of graded susceptibility there are many mild cases, and the incubation time in different individuals may be from 3 to 30 days, indicating variable resistance. The fact that about 70 per cent of the carriers are women suggests that the constitutional characteristics which make it possible for individuals to endure the presence of the organisms are in some way sex-linked in their inheritance. The evidence with respect to typhoid carriers, diphtheria carriers, scarlet-fever carriers, poliomyelitis-virus carriers, etc., makes it seem probable that "carriers" enter into the dissemination of many other milder infections, and... 

Nephrogenic diabetes insipidus (NDI) is characterized by renal tubular resistance to the antidiuretic effect of arginine vasopressin (AVP). NDI may be inherited as an autosomal dominant or X-linked recessive disorder. The autosomal dominant form of NDI results from mutations of the aquaporin 2 gene (AQP2). AQP2 encodes a water channel of the renal collecting duct. Its disruption causes autosomal dominant NDI (113,114) and occasionally recessive forms of the disease. 

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