Protein synthesis in human skeletal muscle tissue: influence of insulin and amino acids

Abstract. The effects of a mild stimulation of endogenous insulin secretion on the rate of incorporation in vitro of amino acids into human skeletal muscle protein were compared with the effects on this rate of adding insulin and amino acids in vitro . An intravenous infusion of 0.83 mmol glucose per kg body weight increased both plasma glucose and insulin levels significantly. The rate of incorporation of leucine into protein in isolated muscle fibres was significantly higher if the subjects had received the glucose infusion. Both insulin and a high concentration of amino acids in the incubation medium stimulated this rate. Amino acids stimulated the rate more than insulin and insulin did not further stimulate the amino acid-stimulated rate. On the other hand, the stimulation of the rate of incorporation by amino acids was the same whether the subjects had received saline and were thus in a basal state or whether they had been infused with glucose (which itself stimulated the rate). The rate of incorporation of leucine was correlated with the tissue concentration of RNA but the correlation was weaker when the rate was stimulated by amino acids than under other experimental conditions. Leucine stimulated the rate of incorporation of phenylalanine but phenylalanine did not stimulate the rate of incorporation of leucine.
It is concluded that the rate of incorporation rate of amino acids into protein in isolated human skeletal muscle fibres is subjected to hormonal and amino acid control.     

Decreased exercise capacity,strength, physical activity level and quality of life in adult patients with familial Mediterranean fever

Background Familial Mediterranean fever (FMF) is a systemic autoinflammatory disease that causes recurrent attacks of fever, polyserositis, arthritis or skin eruptions, resulting in pain in the abdomen, muscles, joints and chest. All of these might lead to a reduction in exercise capacity, muscle strength, physical activity level (PAL) and quality of life (QoL). Therefore, assesment of these parameters are important. The aim of this study was to assess exercise capacity, muscle strength, PAL, and QoL in patients with FMF as compared to controls.Materials and methodsA total of 40 subjects with FMF and 36 healthy control subjects participated in the study. The 6-minute walk test (6MWT) was used to assess exercise capacity. Muscle strength measurements for shoulder flexors, extensors and abductors, hip flexors, extensors and abductors, knee flexors and extensors, and ankle dorsiflexors were evaluated by hand-held dynamometer. PAL was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). QoL was investigated by Nottingham Health Profile (NHP).Results Significant differences were found between patients and healthy subjects for 6MWT (p = 0.003), muscle strength of ankle dorsiflexors (p = 0.001), hip flexors (p = 0.047), extensors (p = 0.003) and abductors (p = 0.004), total scores of IPAQ-SF (p = 0.004), and pain (p < 0.001), physical mobility (p < 0.001) and energy level (p = 0.026) subscales of NHP. However, there were no significant differences between groups for the shoulder flexion (p = 0.089), extension (p = 0.440) and abduction (p = 0.232), hand grip strength (p = 0.160) , and knee flexion (p = 0.744) and extension (p = 0.155) muscle strength and emotional reaction (p = 0.088), sleep (p = 0.070) and social isolation (p = 0.086) subsets of NHP.ConclusionSubjects with FMF demonstrated lower exercise capacity, muscle strength, PAL and QoL than healthy peers. Therefore, it is important to evaluate and improve these parameters in patients with FMF.     

A Double-blind Placebo Controlled Study of Male Alcoholics Given a Subcutaneous Disulfiram Implantation

Twenty-one alcoholics participated in a double blind study to elicit information of the clinical effect of implanted disulfiram. They were randomized to either of two groups, 11 patients to the placebo group and 10 patients to the disulfiram group. Each patient was subjected to seven sessions of intravenous ethanol challenge, once before and six times during the first 20 weeks after implantation. The acute ethanol challenge did not result in any differences between the groups with respect to blood ethanol and acetaldehyde concentrations. No patient showed any clinical signs of disulfiram-ethanol reaction. After a study period of 20 weeks no significant differences were found between the groups with regard to the reduction in average ethanol consumption, days from implantation to the first drink and number of abstinent weeks. Our results do not support the idea that a 1 g disulfiram implant has any pharmacological or clinical action.     

Stresses in the anchor crowns of a metal-ceramic bridge in model experiments

A four-unit principal model bridge was used. The stresses in the porcelain part of an anchor crown were analysed. When the middle of the span was loaded tensile stresses appeared in the outer surface of the porcelain and compressive ones in the interface. Greater stresses were found when the anchor crown was loaded itself. They were not critical, however, when the gold thickness was > 3 mm.     

Dental cementum apposition as an indicator of age

Abstract – The purposes of the present investigation were to examine various ways of measuring cementum thickness, to study its relationship with age, and to consider what contribution this factor might offer in methods for age estimation. The amount of dental cementum apposition was studied in 1000 teeth, excluding molars, from a Caucasian population. Cementum thickness was estimated according to the scoring methods suggested by G ustapson and by J ohanson . In addition, the width of the cementum was measured at the apex and also at approximately one third of the root length from the apex. Statistical analyses using the SPSS package in a Cyber computer indicated a symmetric left/right distribution of cementum thickness. The sum of the cementum thickness on vestibular and lingual surfaces, measured at one third of the root length from the apex, showed the strongest correlation with age (r = 0.40 to 0.65). A reduced rate of cementum apposition was observed in the elderly. Also, maxillary teeth had more cementum on the lingual than on the vestibular surfaces. A tendency was noted for less cementum to occur in women than in men and on teeth removed from deceased persons or extracted for pathologic reasons. Correlation coefficients indicated that, for at least some types of teeth, the cementum thickness might give a significant contribution to statistical methods of age assessment.     

Stresses in a cantilever metal-ceramic bridge in model experiments

The stresses in the porcelain part of the last anchor crown in a cantilever bridge was analysed when loaded. The experiments were made with a model bridge. The load directions were vertical and horizontal. The critical load at the end of a four unit bridge was calculated to about 200 N. When the load direction was perpendicular to the axis of the pontic the critical load was estimated to 50 N.