Solid phase synthesis and characterization of two canine gut gastrin-releasing peptides

Two canine gastrin-releasing peptides originally isolated from gut tissue extracts have been synthesized by solid phase methodology and purified by preparative reverse phase high performance liquid chromatography (RP-HPLC). The synthetic gastrin-releasing peptides GRP1-27 and GRP 5-27 were characterized with regard to homogeneity and composition using nine different RP-HPLC systems, mass spectroscopy, amino acid analysis, Edman degradation, methionine oxidation, and peptide mapping with tryptic, Staph. aureus V8 protease and cyanogen bromide cleavage (the latter two systems performed only with GRP 1-27). Although a scarcity of the natural products prevented quantitative biological comparison of the synthetic and natural peptides, they were found to elute identically on RP-HPLC co-chromatography and similar dose dependent biological potencies were observed in canine antral muscle tissue contraction experiments. Indeed, all the peptides containing the bombesin-like car-boxyl terminal decapeptide sequence studied to date have similar biological activities.     

Functional unilateral posterior crossbite. Orthodontic and functional aspects

summary The purpose of the study was to evaluate the effect of early orthodontic treatment of functional unilateral posterior crossbite (FUPC) and to evaluate temporomandibular function in the short and long term. Orthodontic treatment consisted of slow expansion of the maxillary dental arch by means of a removable expansion plate, with flat coverage of the occlusal surfaces of the left and right posterior teeth. Evaluation of the occlusion showed a strong correlation between the crossbite side and the direction of the RCP-ICP slide and with the side of first occlusal contact in RCP. In 26 of 27 children that were treated (one withdrew), the average time required for correction of the crossbite was 7 months, followed by a retention period, on average, for 6 months after completion of treatment. Early orthodontic treatment resulted in an elimination of occlusal disturbances, and the crossbite remained stable on follow-up during an average of 8 years after the retention period, except in two children with a class III tendency. In nine other children an orthodontic anomaly had developed requiring further treatment (two children showed crowding and seven children showed a class II malocclusion). This study showed that FUPC can be treated adequately by early orthodontic intervention; however, its correction does not guarantee the absence of functional disturbances at a later age. Therefore, FUPC should be treated early in order to achieve normal growth and development rather than to prevent temporomandibular disorders.     

Cytophotometric DNA determination in human astroglial tumours

The DNA content is determined by the cytophotometric method in 16 astroglial tumours, classified according to the degree of clinical malignancy. The values are compared to those found in non-tumoural astrocytes. This method appears to be more reliable in assessment of the degree of malignancy of the tumour in biopsy material than histological criteria and the mitotic index. It is also shown to be of great value in cases where the biopsy is taken at the margin of the tumour and in which malignant histological features are missing.     

Normal diastolic filling patterns of the left ventricle

Pulsed Doppler measurements on both sides of the mitral valveand M-mode left ventricular echocardiograms were performed in215 healthy subjects, 120 males and 95 females, between oneand 65 years old, in order to evaluate normal diastolic fillingpatterns of the left ventricle. The relation between the maximumblood velocity during early passive filling (Ewave) and duringatrial contraction (A wave) was computed from the Doppler spectraobtained proximal and distal to the mitral valve, resultingin the EA ratio. The influence on the EA ratio of age, gender,body surface area, blood pressure, heart rate, PR interval,respiration, wall thickness and basal wall mass of the leftventricle was investigated. The study showed that the EA ratio measured proximal to themitral valve (in the left atrium) was significantly smallerthan the EA ratio measured distal (in the left ventricle) andthat the only prominent relations with the EA ratio were thosewith age and heart rate. The EA ratio declines with age: proximalto the mitral valve from approximately (medians) 2.5 to 1 anddistal to it from 3.5 to 1.5. All other physiological variablesare weakly related or unrelated to the EA ratio in this groupof healthy subjects.