Effects of irrigation temperature on heat control in vitro at different drilling depths

Purpose: Thermal injury during implant bed preparation has a major influence on implant osseointegration and survival. This study investigated the effectiveness of the temperature of the saline solution used for heat control during drilling.
Material and methods: Fresh frozen edentulous segments of bovine mandibles were sectioned into 12 × 6 cm pieces. Thermoresistors were placed 0.5 mm from the drilling cavity walls, at depths of 3, 7, and 12 mm. Signals from the three thermoresistors were analyzed using ORIGIN 5.0 software.
Results: The maximum temperatures during drilling without irrigation were 50.9, 47.4, and 38.1°C at depths of 3, 7, and 12 mm, respectively. With irrigation using saline at 25 and 10°C, the maximum temperatures at a depth of 12 mm were 37.4 and 36.3°C, respectively. All other measurements with both 25 and 10°C saline were below body temperature.
Discussion and conclusion: This experimental in vitro study showed that more heat was generated in the superficial part of the drilling cavity than at the bottom. Therefore, external irrigation at room temperature can provide sufficient cooling during drilling. Lower temperature saline was more effective in cooling the bone, and irrigation of the site should be continued between the drilling steps.     

Magnification-corrected photodynamic therapy

Background To present a method for performing photodynamic therapy (PDT) with a constant predictable light fluence based on actual laser spot magnification. Methods A calibrated Gullstrand-type model eye with a scale of half circles in the centre of the artificial fundus was used for this study. The axial length of the model eye was set to different values ranging from 20 to 31 mm, and the actual laser spot magnification of four indirect condensing laser lenses were determined using a PDT laser unit. Results Equations for determining the actual laser spot magnification were calculated for each laser lens. The total change in laser spot magnification from hyperopia (axial length 20 mm) to myopia (axial length 31 mm) was −20% to +24.8% for Mainster Standard lens (Ocular Instruments Inc, Bellevue, Washington, USA), −15.7% to +27.7% for Mainster Wide Field lens (Ocular Instruments Inc), −16.3% to +33.1% for Volk Transequator lens (Volk Optical Inc, Mentor, Ohio, USA), and −19.2% to +24.4% for Volk PDT Laser lens (Volk Optical Inc). Conclusions Axial length of the eye has a considerable effect on PDT laser spot magnification when an indirect laser lens is used. By calculating the actual laser spot magnification in conjunction with knowledge of the true greatest linear dimension of the neovascular lesion, the clinician may be able to deliver a constant predictable amount of light fluence to the fundus independent of the axial length of the PDT treating eye. No Grant/Financial Support. The authors have no financial interest in any of the products discussed in this article.     

Results of fundus perimetry after resorbed premacular hemorrhages under the internal limiting membrane in 10 patients

BACKGROUND: During their acute phase, premacular hemorrhages under the internal limiting membrane induce an absolute scotoma. It is generally suspected that extravasal blood has a toxic effect on the neuroretina. The objective of this study is to investigate whether one can indeed detect sensoric defects after resorbed hemorrhages under the internal limiting membrane. MATERIALS AND METHODS: Our patient group consisted of 10 patients with resorbed premacular hemorrhages, which had been caused by either Vasalva-Manouver or arterial macroaneurysms. In order to avoid visual field defects due to other causes, patients with diabetes, retinal vein occlusion and glaucoma were excluded from this study. The investigation was carried out with the Scotometry Programme Vers. 2.01 of the Rodenstock Scanning Laser Ophthalmoscope. Furthermore, fundus photographs were taken. RESULTS: Under condition of no pre-existing retinal pathologies, no scotomas could be revealed at the site of the preretinal hemorrhage after full resorption. Relative or absolute scotomas could only be found in cases of pre-existing epiretinal gliosis, pigmentepitheliumdefect, persistent subretinal hemorrhages or scars. CONCLUSION: Since no sensoric defects of the retinal receptors could be detected, the hypothesis of the extravasal blood having a direct toxic effect on the neuroretina, could not be confirmed in this patient group.     

Leukoaraiosis in stroke patients

Pathogenesis of leukoaraiosis (LA) is not clearly understood and its significance in patients with stroke remains undetermined. In the Neurology Department of Ankara Hospital, computed tomography (CT) examination of brain was performed for various reasons in 288 patients. LA was detected in 178 patients by the use of brain CT. Patients with LA had a higher incidence of hypertension history (70.8%) when compared with the non-LA group (57.3%; p <.05). There was no statistically significant difference in terms of sex, mean age, smoking, diabetes mellitus, history of cerebrovascular disease, cardiac failure, ischemic cardiac disease between patients with and without LA. We showed that LA is related to hypertension but not related to age, diabetes mellitus, or cardiac disease in our patient population.     

Studies on the vascular effects of the fractions and phenolic compounds isolated from Viscum album ssp. album

Viscum album L. has been used in the indigenous system of medicine for treatment of various diseases such as atherosclerosis and hypertension. In the literature, phenylpropan and flavonoid derivatives were suggested to play a role in the inhibition of cyclic adenosine monophosphate (cAMP)-phosphodiesterase (PDE) and a correlation was proposed between the in vitro inhibition of PDE and in vivo pharmacological activity. The vascular effects of the phenolic compounds and subfractions isolated from n-butanolic fraction of V. album ssp. album were studied on noradrenaline-contracted rat aortic rings. Isolated phenolic compounds (Syringin (VA-1), Coniferin (VA-9), 5, 7-dimethoxy-flavanone-4'-O-[beta-D-apiofuranosyl(1-->2)]-beta-D-gl uco pyranoside (VA-4)) produced concentration-dependent contractions in rat aortic rings. Only one compound (Kalopanaxin D (VA-15)) displayed very slight relaxant response. The weak concentration-dependent relaxing effect of the subfractions gave the idea that vasodilator activity were observed in the less polar subfractions. In addition, there was no clear correlation between the weak relaxant effects of subfractions and an inhibitory effect on cAMP-PDE.     

Pharmacokinetics and clinical evaluation of 125I-radiolabeled humanized CC49 monoclonal antibody (HuCC49deltaC(H)2) in recurrent and metastatic colorectal cancer patients

INTRODUCTION: CC49 is an antitumor monoclonal antibody that is promising for use in radioimmunoguided surgery (RIGS). However, the murine antibody has been limited by human antimouse antibody (HAMA) response and slow clearance. This study examined the pharmacokinetics and tissue localization of a humanized domain-deleted CC49 antibody (HuCC49DeltaC(H)2 MAb) in humans. METHODS: Twenty-one patients with colorectal carcinoma were given 1 mg intravenous (I.V.) bolus of HuCC49DeltaC(H)2 MAb radiolabeled with 2 mCi (125)I after thyroid blockade. The level of circulating HuCC49DeltaC(H)2 MAb was measured daily as precordial counts using a handheld gamma-detecting probe. Each patient underwent an exploratory laparotomy on postinjection days 3-20. Gamma counts were measured at normal organs, aortic bifurcation (AB), and both clinically evident and occult tumors. RESULTS: Precordial and AB gamma counts showed an excellent linear correlation. HuCC49DeltaC(H)2 MAb followed a two-compartment pharmacokinetic model. Normal organs and AB showed similar exposures to HuCC49DeltaC(H)2 MAb, while HuCC49DeltaC(H)2 MAb favorably distributed into tumors from day 3. Intestinal and metastatic liver lesions showed the highest partition coefficients. All patients showed no HAMA response. DISCUSSION: C(H)2 region deletion of HuCC49DeltaC(H)2 MAb did not alter the pharmacokinetics compared to murine CC49. The favorable partition coefficient K of HuCC49DeltaC(H)2 MAb into tumors supports its use in RIGS.     

The roles of HRCT and clinical parameters in assessing activity of suspected smear negative pulmonary tuberculosis

BACKGROUND: Smear-negative pulmonary tuberculosis (SNPTB) constitutes a major problem in countries with a moderate or high TB prevalence. The value of high-resolution computed tomography (HRCT), chest x-ray and other clinical findings in determining activity of SNPTB were investigated. METHODS: The study population consisted of 85 patients with suspected SNPTB, of whom 52 were confirmed as active pulmonary TB according to either culture positivity for Mycobacteriun tuberculosis or demonstration of caseous granulomatous inflammation. The remaining 33 patients accepted inactive TB sequel. RESULTS: Cough and expectoration were significantly frequent in inactive group whereas chest pain was detected higher in active patients. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of HRCT in detecting disease activity were 88, 88, 92, 83 and 88%, respectively. Centrilobular nodules, other non-calcified nodules, consolidation and cavity were significantly higher on HRCT in active group. Chest x-ray scores that were graded 1 to 3 showed a linear trend for the disease activity. CONCLUSIONS: HRCT has good diagnostic value in detecting activity of SNPTB, and some clinical findings may help in predicting the activity.