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Different approaches to the mandibular condyle have been described. In this paper, a modified trans-oral technique to access the mandibular condyle is described and illustrated. This technique was used in a small group of patients; the clinical outcomes are promising. The technique can be used in various temporomandibular joint (TMJ) operations, such as condylar resection, high condylectomy or tumor removal. It provides adequate intra-oral surgical access to the mandibular condyle and avoids complications from extra-oral approaches to the TMJ.

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The activity of the complete arginine pathway-urea cycle was assessed in intact plant cells by employing the commercial enzymes arginase (EC 3.5.3.1) and urease (EC 3.5.1.5) to determine the amount of NaH14CO3 incorporated into [guanido-14C]arginine and/or into [14C]urea during a 3-h labeling period. Recovery of [guanido-14C]arginine was linear from 5 to 1000 nmol/g tissue and averaged 80 +/- 5% (mean +/- SE, N = 3). The procedure is reliable, inexpensive, well suited to the simultaneous analysis of numerous samples, and significantly more sensitive than existing methods. The method is ideally suited for assessing the activity of the complete arginine biosynthetic pathway in intact cells. In addition, the method has the distinct advantage of providing simultaneous measurement of the amount of NaH14CO3 accumulating in arginine relative to the amount accumulating as urea. Evidence is presented demonstrating that both the activity of the arginine pathway and the relative amounts of [guanido-14C]arginine and [14C]urea synthesized from NaH14CO3 were influenced by changes in the level of ornithine, NH+4, or phosphorus available to plant tissues.

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Lovatt et al. (1979 Plant Physiol 64: 562-569) have previously demonstrated that end-product inhibition functions as a mechanism regulating the activity of the orotic acid pathway in intact cells of roots excised from 2-day-old squash plants (Cucurbita pepo L. cv Early Prolific Straightneck). Uridine (0.5 millimolar final concentration) or one of its metabolites inhibited the incorporation of NaH(14)CO(3), but not [(14)C]carbamylaspartate or [(14)C]orotic acid, into uridine nucleotides (SigmaUMP). Thus, regulation of de novo pyrimidine biosynthesis was demonstrated to occur at one or both of the first two reactions of the orotic acid pathway, those catalyzed by carbamylphosphate synthetase (CPSase) and aspartate carbamyltransferase (ACTase). The results of the present study provide evidence that ACTase alone is the site of feedback control by added uridine or one of its metabolites. Evidence demonstrating regulation of the orotic acid pathway by end-product inhibition at ACTase, but not at CPSase, includes the following observations: (a) addition of uridine (0.5 millimolar final concentration) inhibited the incorporation of NaH(14)CO(3) into SigmaUMP by 80% but did not inhibit the incorporation of NaH(14)CO(3) into arginine; (b) inhibition of the orotate pathway by added uridine was not reversed by supplying exogenous ornithine (5 millimolar final concentration), while the incorporation of NaH(14)CO(3) into arginine was stimulated more than 15-fold when both uridine and ornithine were added; (c) incorporation of NaH(14)CO(3) into arginine increased, with or without added ornithine when the de novo pyrimidine pathway was inhibited by added uridine; and (d) in assays employing cell-free extracts prepared from 2-day-old squash roots, the activity of ACTase, but not CPSase, was inhibited by added pyrimidine nucleotides.

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A prospective trial of the treatment of malignant and premalignant skin lesions of the leg by excision and skin graft under local anaesthesia as an outpatient procedure has shown encouraging results.

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Low-lactose milk was produced by incubating cow's milk with yeast lactase. Sixteen lactose tolerant and 15 intolerant volunteers ingested 500 ml of the product twice daily for 1 month. During the testing period all subjects received on three occasions the same volume of unmodified milk in double-blind tests. Symptoms recorded throughout the study and for an additional 15 day base-line observation period were: diarrhea, abdominal pain and distention, flatulence, heartburn, and headache. Low-lactose milk acceptance was excellent. No significant differences were found between tolerants and intolerants during the base-line period and while ingesting low-lactose milk. By contrast, unmodified milk induced severe symptoms only in the intolerants. Availability of low-lactose milk and of its by-products allows consumption of greater volumes of this highly nutritious food by subjects with lactose intolerance with none or less symptoms compared to unmodified milk.

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The protein requirement and the efficiency of protein used were studied in young and old adult human subjects. Protein intake levels (N X 6.25) of 0.4, 0.8, and 1.6 g/kg body weight per day from a combination wheat-soy-milk mixture were fed. Caloric intake was held constant at 40 kcal/kg body weight per day throughout the 11-day study of each dietary period. No significant differences were observed in their protein requirement, efficiency of protein use or the ability to adapt to changes of protein intake levels. Protein digestibility was not impaired in the aged. It is concluded that the protein requirement and the efficiency of protein use are not affected by the aging process.

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