The etiology of feline dental resorptive lesions is unknown, but some evidence suggests that interactions between components of the periodontium may be initiating factors in the development of these lesions. In the present study, 22 clinically normal teeth were harvested from 7 cats. The teeth and periodontium were radiographed and examined histologically. In addition, 14 of the 22 teeth were examined histometrically. Two teeth were histologically normal with an open apical foramen and two were normal with a closed apical foramen. Histological evidence of periodontal ligament degeneration without cementum resorption was observed in 8 teeth, and varying degrees of cementum resorption were observed in 10 teeth. Mandibular molar and premolar teeth had distal drift, and mandibular canine teeth had mesial drift. Alterations in the periodontal ligament may represent a preclinical stage of dental resorption.
Feline tooth resorption has been widely reported in domestic cats and sporadically described in other felidae. The goal of the present study was to determine the prevalence of tooth resorption and to report other dental problems in a population of wild felidae. Observations of dental disorders and anomalies were made in skulls from 73 wild felidae (cheetahs, leopards, caracals, African wildcats, and lions) originating from Namibia. In addition, radiographs were taken in 43 cases to determine signs of bone and root pathology. Radiographs showed varying stages of tooth resorption in 16.0% of the specimens. Other dental anomalies found included fused teeth, supernumerary roots, or missing teeth. The prevalence of dental resorption in wild felidae was lower than reported in the domestic cat.
Are there feline odontoclastic resorptive lesions (FORL) in large cats? Macroscopic and radiological investigations of teeth of a zoo leopard, two wild lions and a wild leopard revealed that there are lesions identical to those found in teeth of domestic cats. Because of the radiological and clinical similarity between resorptive lesions and caries, additional examinations were carried out in order to differentiate between those two conditions. Based on the results of investigations such as Rhodamin B dye test, fuchsin/acetic light green staining, hardness measurements by the Knoop-diamond (KHN), and electron-microscopy, we conclude that FORL also occur in captive and wild large cats.
1. Alcohol dehydrogenase isoenzymes BB were isolated from human livers of both "normal" and "atypical" phenotypes [l]. Their pH-rate profiles, their behaviour on CM-cellulose and the number of hybrids formed with horse subunit A show that the "atypical" isoenzymes contain subunits B1 and B,, the "normal" one only subunit B,. These results indicate that most "atypical" individuals genetically represent heterozygotes.2. A high degree of homology between horse subunit A and human subunits B is found. However, the human isoenzymes have a molecular weight of 87000 and contain about 410 amino acid residues, 6 tyrosines and 3 tryptophans per subunit.3. The sequence of one tryptic peptide from subunit B, is Phe-Ala-Lys and is altered to Phe-ProLys in the subunit B,. This substituted residue is located in a region which corresponds to the coenzyme-binding site of the horse enzyme.The models of the subunit composition of the multiple molecular forms of human liver alcohol dehydrogenase suggest that the dimeric isoenzymes are formed by combination of four different subunits [l--41. A polymorphism of the human enzyme has been observed in addition to this heterogeneity [5], and the term "atypical" variant was introduced. Screening tests discriminating between the "normal" and "atypical" phenotypes were devised on the basis of several differences in catalytic parameters of the enzymes. With these a bimodal distribution has been found in several populations [6-91.In liver homogenate a higher specific activity for ethanol oxidation and a shift of the pH optimum to a lower value represent the main characteristics of the "atypical" enzyme when compared with the "normal" one. Both differences were found to pertain to isoenzymes BB isolated from "normal" and "atypical" livers, suggesting that subunit B exists in a variant form [l]. According to the genetic model proposed by Smith et al.[8] two alleles occur at the gene locus coding for subunit B; they are responsible for the synthesis of either the "normal" (B,) or "atypical" (B2) subunit. Therefore three groups of individuals are expected with respect to their subunit composition : homozygotes with subunit B1 only, homozygotes with subunit B2 only and heterozygotes with both subunits B1 and B2. In "atypical" livers two isoenzymes AB were found [l], one with "atypical" (AB,) and one with "normal" (AB,) catalytic properties. This result indicated that "atypical" livers could stem from heterozygous individuals.Based on the genetic model for the polymorphism and the known primary structures of two subunits of the horse enzyme [lo], as well as the sequence of some peptides from human liver alcohol dehydrogenase [ll], it seemed of interest to search for the difference in primary structure between subunits
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