Change in temperature of subjacent bone during soft tissue laser ablation

In tissues that closely approximate bone, sufficient heat may be transferred to the bone during laser surgery to cause damage and/or necrosis. To date, there have been few studies examining the temperatures elicited at the bone surface as a result of laser application to the overlying soft tissues. The purpose of this investigation was to determine, under in vitro conditions, temperature changes at the bone/soft tissue interface during laser ablation with CO2 and Nd:YAG lasers used with and without (w/wo) air/water coolant. Experimental specimens consisted of 5 mandibles from freshly sacrificed hogs; laser treatment sites were the buccal and lingual attached gingiva of the molars and the lingual keratinized mucosa of the incisor region. CO2 and Nd:YAG lasers were used w/wo coolant at power settings of 4 to 8 W and 5 to 9 W, respectively. Temperature changes were measured with a copper constant thermocouple contained within a 21 gauge hypodermic needle. In comparing the lasers at comparable energy densities w/wo coolant, temperature increases at the bone/soft tissue interface ranged from 8.0 to 11.1 degrees C with the Nd:YAG and 1.4 to 2.1 degrees C with the CO2. Similarly, in comparing the times required for the interface to return to baseline temperature following removal of the laser, values ranged from approximately 143 to 205 and approximately 119 to 139 seconds for the Nd:YAG and CO2, respectively. Results from this study suggest that, at energy densities equal or above those reported here, the increase in temperature at the bone surface as a result of periodontal soft tissue surgery with the Nd:YAG laser could be damaging, especially if the exposure is prolonged.     

Combined therapy with 5-aminosalicylic acid tablets and enemas for maintaining remission in ulcerative colitis: a randomized double-blind study

OBJECTIVES: To assess the efficacy of a combination of oral and topical 5-aminosalicylic acid (5-ASA) for the maintenance treatment of ulcerative colitis, we undertook a double-blind randomized clinical trial. METHODS: Patients aged 18 to 65 yr (with disease extent greater than proctitis only) were eligible for inclusion in the study if they met the following criteria: (a) history of two or more relapses in the last year; (b) achievement of remission in the last 3 months (with maintenance of remission for at least 1 month). Patients enrolled in the study were randomly assigned to one of the two following 1-yr treatments: (1) combined therapy with 5-ASA tablets 1.6 g/day and 5-ASA enemas 4 g/100 ml twice weekly; (2) oral therapy with 5-ASA tablets 1.6 g/day and placebo enemas/twice weekly. The main end point of the study was the maintenance of remission at 12 months. RESULTS: Upon completion of the study, relapse occurred in 13 of 33 patients in the combined treatment group versus 23 of 36 patients in the oral treatment group (39 vs 69%; p = 0.036). No significant side effects related to treatment were observed in either group. A simplified pharmacoeconomic analysis shows that this form of combined treatment can have a favorable cost-effectiveness ratio. CONCLUSIONS: Our results indicate that 5-ASA given daily by oral route and intermittently by topical route can be more effective than oral therapy alone. This form of combination treatment can be appropriate for patients at high risk of relapse.     

Repression of the minimal HLA-B promoter by c-myc and p53 occurs through independent mechanisms

Major Histocompatibility Complex (MHC, HLA in humans) class I antigens play an important role in cellular immunology by presenting antigens to T cells. Downregulation of MHC class I expression is thought to be a mechanism by which tumor cells escape from T cell-mediated lysis. In primary human melanomas and melanoma cell lines, HLA-B expression is frequently downmodulated, correlating with elevated expression of the c-myc oncogene. Transfection experiments have shown that c-myc induces HLA-B downregulation through a -68 to +13 base pairs (bp) core promoter fragment, containing CCAAT and TATA-like (TCTA) boxes. Since (i) c-myc has been reported to activate the human p53 promoter and (ii) p53 is capable of repressing a large array of basal promoters, we investigated whether c-myc-induced HLA-B abrogation is mediated by p53. In this article, it is shown that the HLA-B core promoter is indeed repressed by wild-type p53, making p53 a candidate for mediating c-myc-induced HLA-B downregulation. However, transfection of c-myc into p53-null cell lines still resulted in suppression of the basal HLA-B promoter, demonstrating that c-myc and p53 repress the minimal HLA-B promoter through independent mechanisms.     

Appearance and maturation of T-cell subsets during rat thymus ontogeny

This study measured the release of glutamate (Glu) and aspartate (Asp) amino acid transmitters in the ventrocaudal compartment of the rat periaqueductal gray (PAG) following exposure to unilateral peripheral inflammation. The release of endogenous Glu and Asp from the rat ventrocaudal PAG was monitored with the microdialysis technique in unanesthetized, unrestrained rats. There was significant increase (1,300%) in the basal concentrations of Glu release in the 7 days Complete Freund's Adjuvant (CFA) treated group compared to 24 h mineral oil control group. Amino acid release was induced by infusing veratridine (75 microM, a sodium channel activator) directly through the 1 mm long dialysis probe. Perfusion of veratridine into the ventrocaudal PAG resulted in significant elevation of Glu and Asp amino acids. In the 24 h and 7 days CFA treated rats, veratridine-evoked release of Glu was significantly decreased in the lateral ventrocaudal PAG compared to control rats injected with mineral oil (CFA vehicle). The peak minus baseline concentrations of Glu in 24 h and 7 days CFA treated groups decreased 55.7% and 43.9%, respectively. In contrast, The basal and the peak minus baseline concentrations of Asp showed no significant change between control group and 24 h and 7 days CFA treated animals. The results provide direct evidence that Glu excitatory amino acid may be involved in nociception/nociception modulation pathway in the ventrocaudal PAG.     

Torsional injury resulting in disc degeneration in the rabbit: II. Associative changes in dorsal root ganglion and spinal cord neurotransmitter production

An ornamental pet fish was diagnosed with a spinal fracture and subluxation involving truncal vertebrae 5 and 6 (T5-T6) using conventional radiography, nuclear scintigraphy, and computed tomography. Attempts to evaluate the dynamic nature of the lesion using conventional fluoroscopy in the unanesthetized, moving patient were unsuccessful. Adaptation of imaging techniques to accommodate a fish patient was not difficult and diagnostic images were obtained. The use of multiple imaging techniques was useful in the diagnosis and determination of the treatment plan of the spinal fracture in this patient.     

Cross-sectional study of oral Candida carriage in a human immunodeficiency virus (HIV)-seropositive population: predisposing factors, epidemiology and antifungal susceptibility

The Candida species isolated from oral rinses of 130 human immunodeficiency virus (HIV) infected patients were compared with those of 130 healthy non-matched volunteers. The oral rinses were plated on CHROMagar Candida medium (CAC) and on CAC supplemented with 10 micrograms (CF10) and 100 micrograms (CF100) of fluconazole per ml. The prevalence of non-albicans Candida spp. in oral rinses of HIV-infected patients and their correlation with the clinical and epidemiological characteristics of the patients were studied. Susceptibility of the Candida spp. isolated was determined by a microbroth dilution method based on the NCCLS reference procedure. Results of susceptibility tests of the yeast isolates were compared with their growth at the time of isolation on CAC supplemented with fluconazole. Thirty-five (30.7%) strains of non-albicans Candida spp. were isolated from the HIV-positive population, vs. seven (15.9%) from the immunocompetent population. Growth on CF10 correlated in 96% of the cases with fluconazole minimum inhibitory concentration (MIC) > 8 micrograms ml-1. Smoking and use of azoles were significantly associated with oral carriage of non-albicans Candida spp. (P < 0.05). The prevalence of non-albicans Candida spp. in HIV-positive persons in oral rinse samples is twice as high as in the HIV-negative population. Smoking and treatment with azoles are risk factors for the oral carriage of non-albicans Candida spp. The isolation of yeasts on CAC plates supplemented with fluconazole allows combination of presumptive yeast identification and fluconazole susceptibility testing.     

Effect of quinapril or metoprolol on heart rate variability in post-myocardial infarction patients

The aim of this study was to examine doctoral theses written by nurses on the same subject, namely diabetes. The five theses were published during three years. The text analysis emphasized the purposes, theoretical framing, methods for collection and analyzing the data, ways of presenting the texts and, finally, the references in the five theses. The findings indicate that the authors make use of different paradigms. Experimental approach was used in some theses and one thesis was based on grounded theory. Two theses could be said to be more concise that the others because they made use of only one technique each--physiological measurements and an open-ended interview. The remainder used of a number of methods--in other words, they were eclectic in approach. The conclusion is that there is a freedom for nurse researcher to affiliate to different scientific traditions inside academia--the two in question here are biomedical research and interpretative traditions inside social science. The author encourage all researchers inside the nursing domain to subject herself to criticism and reflection to the same extent as she analyzes other people or phenomena in order to increase epistemological awareness of the use of research tools, perspectives and theories.     

Atomic and molecular imaging at the single-cell level with TOF-SIMS

A complete cold chain freeze-fracture methodology has been developed to test the feasibility of using time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging for the molecular analysis of frozen hydrated biological samples. Because the technique only samples the first few monolayers of a sample, water on the surface of a sample can be a major source of interference. This problem can be minimized by placing a cold trap (fracture knife and housing at -196 degrees C) near the fractured sample that is held at a warmer temperature (-97 to -113 degrees C). This results in removal of surface water and prevents condensation on the surface. Although this approach is effective, it has been found that sample warming needs to be carefully controlled due to the volatility of other matrix molecules and the morphological effects imparted onto the cell surface during drying. By utilizing the above handling technique, it has been possible to demonstrate for the first time that TOF-SIMS imaging technology can be used to obtain images of molecular species across a cell surface with a submicrometer ion probe beam. Images of small hydrocarbons and the deliberately added dopants DMSO and cocaine have been obtained with TOF-SIMS of the single-cell organism Paramecium.     

Sinus histiocytosis with massive lymphadenopathy: presentation as giant granuloma annulare and detection of human herpesvirus 6

The authors report a case of laparoscopic resection of a bladder diverticulum performed at the same time as endoscopic treatment of its presumed cause. Dissection of the diverticulum, particularly its neck, and dissection of diverticula of the ureter and vas deferens are facilitated by magnification of the video image. This approach is only indicated in particular anatomical sites (posterior). The results of this technique must be compared with those of conventional treatments.