Fr?nkel appliance therapy and the temporomandibular disc: a prospective magnetic resonance imaging study.

This prospective clinical study assessed the effect of the Fr?nkel Functional Regulator-II (FR-II) treatment on the position and shape of the articular disc of the temporomandibular joint. The sample included magnetic resonance images of 112 temporomandibular joints taken initially (T1) and after 18 +/- 1 months (T2). The subjects were 56 white Brazilian children who were beginning their pubertal growth spurt. They had Class II Division 1 malocclusions and were selected from 800 children in neighborhood schools. They were randomly dichotomized into either the treated group (treated with the FR-II for 18 months) or the control group (not treated during the observation period). Our findings showed a low prevalence (3.57%) of disc displacement in the 112 temporomandibular joints. Mandibular propulsion with the FR-II had no unfavorable effect on the temporomandibular joints of the treated group; 100% of the patients kept an upper and interposed disc position (closed and open mouth, respectively) at T1 and T2. The control group had 7.1% partial anterior medial disc displacement, both at T1 and T2. Regarding disc morphology, the control group showed biconcave-shaped discs in 82.1% of the joints, statistically similar to the treated group (89.3%) at the beginning of the observation period. At T2, the articular disc morphology of the control group was unchanged, but that of the treated group was significantly more normal (P =.016), progressing from nonbiconcave at T1 (10.7%) to biconcave at T2 (100%). Our results showed that disc displacement is not a complication of functional appliance therapy; in fact, such treatment might help some children with incipient temporomandibular disorders.     

Macromers as intermediates for the synthesis of graft copolymers

Free radical copolymerization of a macromer and a vinylic or acrylic monomer is a novel method of synthesis of graft copolymers. Each macromer unit gives yield to a graft. Accurate characterization of the samples obtained, especially by means of proton NMR, is possible. The distribution of the grafts along the chain is random. The overall molecular weights of the copolymers formed are low, however.     

Tumor cell dormancy induced by p38SAPK and ER-stress signaling: an adaptive advantage for metastatic cells?

The mechanisms that determine whether a tumor cell that has disseminated to a secondary site will resume growth immediately, die or enter a state of dormancy are poorly understood. Although tumor dormancy represents a common clinical finding, studying the mechanisms behind this stage of tumor progression has been challenging. Furthermore, it is thought that dormant tumor cells are refractory to chemotherapy due to their lack of proliferation. However, whether this is the only reason for their chemo-resistance remains to be proven. In this review we summarize recent findings that provide a mechanistic explanation about how stress signaling through the p38(SAPK) pathway and ER-stress signaling may coordinate the induction of growth arrest and drug-resistance in a model of squamous carcinoma dormancy. We further discuss how dormant tumor cells may enter this stage to adapt to strenuous conditions that do not favor immediate growth after dissemination. Finally, we propose that this response may recapitulate an evolutionarily conserved program of life-span extension through adaptation and tolerance to stress.     

Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise

OBJECTIVE: We investigated the effect of supplementation with L-glutamine and L-alanyl-L-glutamine (DIP) on the plasma and tissue glutamine concentrations of exercise-trained rats immediately and 3 hours after a single exercise session until exhaustion. METHODS: Thirty-six male rats were divided into six groups, and then subdivided into groups submitted only to the exhaustion test: control (CON-EXA, n = 6), glutamine (GLN-EXA, n = 6) and DIP-EXA (n = 6), or to the exhaustion test followed by a recovery period lasting 3 hours: control (CON-REC, n = 6), glutamine (GLN-REC, n = 6) and DIP-REC (n = 6). The training protocol consisted of bouts of swimming exercise (60 min x day(-1)) for 6 weeks. During the last 21 days, before sacrifice, the glutamine and DIP groups received a daily dose of 1 g x kg(-1) of glutamine and 1.5 g x kg(-1) of DIP, respectively. The GLN-REC and DIP-REC groups were also supplemented immediately after the exhaustion test. Concentrations of glutamine, glutamate, glucose and ammonia in plasma and of glutamine, protein and glycogen in liver and muscle were evaluated. RESULTS: The time to exhaustion did not differ between groups. A higher concentration of glutamine in the gastrocnemius and soleus muscles was observed for the DIP-EXA group compared to the CON-EXA and GLN-EXA groups (P < 0.05). The DIP-REC group presented a higher plasma and liver glutamine concentration than the CON-REC group (P < 0.05). Muscle glutamine and protein concentration was higher in both the GLN-REC and DIP-REC groups compared to the CON-REC group (P < 0.05). CONCLUSIONS: Chronic supplementation with DIP promoted a higher muscle glutamine concentration than chronic supplementation with glutamine immediately after exercise. However, no significant difference in plasma or tissue glutamine concentrations was observed between acute supplementation with glutamine and DIP during the post-exhaustive exercise recovery period.     

Adenocarcinoma of the colon and rectum: A review of surgical treatment in 302 patients

Summary A retrospective study of 302 patients who underwent surgical treatment for colorectal carcinoma from 1952 to 1971 is presented. Resectability rate was 93.7 per cent. Operative mortality rate was 5 per cent. Complications were recorded in 12 per cent of cases. Recurrence at the anastomotic line occurred in 3.31 per cent. The actuarial five-year survival rate was 44.2 per cent for all types of cancer. The “no-touch” technique utilized after 1968 resulted in increased survival of patients who had Dukes' B and C cancers.