Temporomandibular response to early and late removal of bite-jumping devices

This study was designed to monitor the amount of bone formed after 'early' and 'late' removal of bite-jumping devices and to compare it with that of normal growth. One hundred and thirty-five 35-day-old female Sprague-Dawley rats were randomly divided into seven control (n = 5) and 10 experimental (n = 10) groups. Appliances were fitted to position the mandible forward in the experimental groups. On day 30, the bite-jumping device was removed in two groups ('early' removal) and the rats were sacrificed on days 44 and 60. On day 44 the device was removed in one group ('late' removal) and the rats were sacrificed on day 60. The full-time wear and matched control animals were then sacrificed at different time points. Tissue sections (7 microm) were cut through the temporomandibular joint (TMJ) in the sagittal plane and stained with periodic acid and Schiff's reagent for the evaluation of new bone formation. Newly formed bone was measured using a computer-assisted image analysing system. The results showed that, in the condyle, early removal of the appliance resulted in less bone formation when compared with that of natural growth. Late removal of the appliance resulted in bone formation similar to that of natural growth. In the glenoid fossa, the level of bone formation was similar to that of the control at early and late removal of the appliance. In conclusion, early appliance removal results in subnormal growth of the posterior condyle but not of the glenoid fossa. Increasing the length of mandibular advancement secures normal levels of mandibular growth in the post-treatment period.     

Performance of Sahli and colour scale methods in diagnosing anaemia among school children in low prevalence areas

Our aim was to compare the performance of the Sahli and Colour Scale methods in diagnosing anaemia in school children, where the prevalence of anaemia is low and the haemoglobin level ranges from mild to moderate (8-11 g/dl). The study was conducted in February 2001, in Qena Governorate, Upper Egypt. The haemoglobin level measured by the two methods in each child were compared with the result obtained by using a portable haemoglobin photometer 'HemoCue'. A total of 149 school children were included in the study. Using HemoCue, 17.4% children were anaemic; using the Sahli method (SM), 66.4% children were anaemic; and using the Haemoglobin Colour Scale (HCS) method, 57.7% children were anaemic. Neither method detected any cases of severe anaemia (Hb < 7 g/dl). Both the Sahli and Colour Scale methods are sensitive but have low specificity, giving a high rate of false positive results. Both methods perform perform very similarly in haemoglobin measurement; they fulfil many of the criteria for their use at primary health care level and detect almost all cases of anaemia in a given population, even if the level of anaemia is mild. Standards for collection, handling and disposal of blood samples are guaranteed more easily by the HCS than the SM. Moreover, lay people can easily manage the HCS with success after brief training. We suggest to gradually replace the SM by the HCS method in primary health care (PHC) centres. Where anaemia levels are moderate to mild, the use of SM and HCS as tools to define anaemia prevalence might be limited, as they often label healthy individuals as anaemic. Both methods remain a useful diagnostic tool to confirm the diagnosis of clinically suspected anaemia in areas where the prevalence of anaemia is low and the haemoglobin level ranges from mild to moderate.     

S-adenosyl-methionine-induced apoptosis in PC12 cells

Our previous studies showed that S-adenosyl-methionine (SAM) induced Parkinson's disease-like changes in rat. It caused death to dopamine neurons in the substantia nigra, which appeared shrunken and fragmented, indicative of apoptosis-like changes (Charlton and Crowell [1995] Mol. Chem. Neuropathol. 26:269-284; Charlton [1997] Life Sci. 61:495-502). In this study, we investigated whether SAM causes apoptosis in both undifferentiated PC12 (PC12) cells and nerve growth factor (NGF)-differentiated PC12 (D-PC12) cells. S-adenosyl-homocysteine (SAH), the nonmethyl analog of SAM, was also tested. SAM and SAH (1.0 nM to 10.0 microM) caused lactate dehydrogenase (LDH) release from the PC12 cells and D-PC12 cells; cells with morphological changes and fluorescent DNA fragmentation staining were detected among both PC12 cell and D-PC12 cell. Compared with the PC12 cell, the D-PC12 cell, a postmitotic cell, was more sensitive to the toxic effects of SAM or SAH and presented much greater LDH release, suggesting a lethal effect; surprisingly, the amounts of apoptotic cells did not differ significantly between the two kinds of cells. In medium deprived of exogenous methionine, a decline in LDH release was observed in PC12 and D-PC12 cells. Also, lower levels of intracellular SAM and SAH were observed in the methionine-deleted media, which were reversed by the addition of either SAM or SAH. An antivitamin B(12) monoclonal antibody was added to methionine-depleted medium, resulting in deficiency of both endogenous and exogenous methionine, which caused further decreases in LDH release and reduction in the levels of intracellular SAM and SAH. The preliminary data showed different sensitivities to SAM or SAH between PC12 cell and D-PC12 cells, which suggests that PC12 cell may be more stable as a metabolic model. Apoptosis of PC12 cells was also assessed by PARP cleavage detection, Western blot analysis of Bax and Bcl-2 proteins, and DNA laddering on agarose gel electrophoresis. The proapoptoic protein Bax was dominantly expressed, whereas Bcl-2 was slightly down-regulated by SAM. SAH weakly induced the expression of Bax and slightly decreased Bcl-2 levels. The effects of SAM and its analog, SAH, were demonstrated conclusively to induce apoptosis in PC12 cells.     

Non-invasive molecular detection of bladder cancer recurrence

Transitional cell carcinoma (TCC) is the most common bladder tumor and approximately 90% of bladder TCC are superficial at initial diagnosis. High recurrence rate and possible progression to muscle invasive disease that is eventually indicated for radical cystectomy are established features of these tumors. Therefore, reliable predictors of tumor recurrence are of critical importance for management of superficial bladder TCC. Successful molecular diagnosis of bladder cancer by detecting genetic lesions: loss of heterozygosity (LOH) or microsatellite instability (MSI) in cells exfoliated in urine has been reported by several groups including ours. The aim of our study was to evaluate the predictive potential of microsatellite analysis of cells exfoliated in urine in the detection of superficial bladder TCC recurrence. We studied 47 Caucasian patients with confirmed superficial bladder TCC (37 pTa, 10 pT1) at initial diagnosis. Blood samples were obtained once from every patient whereas urine samples were collected before each cystoscopy (initial and follow-up). Matched DNAs from blood and urine were subjected to microsatellite analysis in a blinded fashion. The follow-up period ranged 12-48 months after tumor resection. Microsatellite analysis correctly identified 94% (44/47) of primary tumors and 92% (12/13) of tumor recurrences. Interestingly enough, 75% (9/12) of tumor recurrences were molecularly detected 1-9 months before cystoscopic evidence of recurrent disease. This study demonstrated clearly that not only urine microsatellite analysis reliably detected superficial bladder tumors, but also was a reliable test for detecting and predicting tumor recurrence in Caucasian patients. These results warrant multicenter randomized trials.     

Relative importance of enhanced glucose uptake versus attenuation of long-chain acyl carnitines in protecting ischemic myocardium

BACKGROUND: A number of experimental studies have shown that increasing glucose use or decreasing accumulation of long-chain acyl carnitines (LCAC) protect ischemic hearts. METHODS: To evaluate the relative importance of these two strategies in protecting ischemic myocardium, isolated rat hearts (n = 6 in each group) were paced at 300 bpm and subjected to 50 min of low-flow ischemia followed by 60 min of reperfusion. Buffer contained 0.4 m mol/l albumin, 0.4 m mol/l palmitate, and 70 mU/l insulin, and either normal glucose (5 m mol/l) (CON), high glucose (10 m mol/l total) (HG, known to increase glucose use), 5 m mol/l glucose and niacin (10 micromol/l) (NIA, known to increase glucose use and decrease LCAC) or carnitine (10 m mol/l) (CAR, known to increase glucose use and decrease LCAC). Separate groups of hearts were perfused in the presence of 10 micromol/l cytochalasin-B (CB), an inhibitor of insulin-sensitive glucose transporters. RESULTS: Ischemic injury, as assessed by creatine kinase (CK) release was diminished by an average of 50% in HG, NIA, and CAR hearts, and the percentage recovery of left ventricular (LV) function with reperfusion was enhanced by approximately 20% compared with CON hearts (P < 0.05 for each comparison). Cytochalasin-B abolished all of the salutary effects. Long-chain acyl carnitines levels were higher in HG hearts compared with NIA- and CAR-treated hearts ( P < 0.05), but ischemic protection and functional recovery was greater in HG hearts. CONCLUSIONS: The data support the adjunctive use of agents that promote glucose uptake during ischemia and suggest that increasing glucose use is more important than decreasing LCAC in the protection against ischemic injury or in the recovery of contractile function.     

Long-term follow-up of surgically treated gallbladder cancer patients

AIMS: Palliative attempts have traditionally led treatment of gallbladder cancer but resection offers the only chance for long-term survival. This study investigates the impact of surgery with curative intent in gallbladder cancer treatment and evaluates prognostic factors for survival. METHODS: Two hundred and sixty-seven patients were admitted for surgical therapy. Sixty received resection with curative intent and form the basis of this analysis. RESULTS: R0 resection (n=45) was a highly significant independent survival predictor (P<0.001). All 5-year survivors (n=10) had tumour-free resection margins. Early T stage (P=0.017) and highly differentiated cancer (P=0.008) had a significant better outcome. Nodal spreading increased by local tumour extension and lymphatic involvement decreased patient survival (P=0.018). Patients' age (>75 years) was without influence on long-term survival. CONCLUSIONS: Long-term survival is possible both in elderly patients and in advanced cancer.