Risk stratification and dental management of the patient with cardiovascular diseases. Part II: Oral disease burden and principles of dental management.

Cardiovascular diseases are the leading cause of death in the United States and most other Western countries. In the United States alone, more than 1 million annual deaths and as many as three times that number of serious consequences can be attributed to these conditions. To provide care to patients with cardiovascular disease, oral health care providers must understand the disease, its treatment, and its impact on the patient's ability to undergo and respond to dental care.     

Evaluation of preoperative chemoembolization using ethiodized oil, cisplatin and gelatin sponge (sandwich therapy) for hepatocellular carcinoma

The significance of preoperative chemoembolization using ethiodized oil, cisplatin and gelatin sponge (Sandwich therapy) for resectable hepatocellular carcinoma (HCC) was evaluated. One hundred and thirteen patients with solitary and less than 10 cm sized HCC who underwent radical hepatic resection were chosen for this study. Fifty-three patients received Sandwich therapy before surgery (Group A), and the remaining 60 patients under-went surgery without any preoperative treatments (Group B). Any background factors between two groups were not significantly different. The anticancer effects of this therapy were evaluated by histologic examination in 31 patients who had preoperative Sandwich therapy. In 22 of 31 patients (71%), the main nodules were completely necrotic. The ratios of patients with complete necrosis in daughter nodules were 7/12 (58%), in portal vein tumor emboli, 7/10 (70%), in intracapsular invasions, 11/21 (52%), in extracapsular invasions, 4/11 (36%). The 4-year disease-free survival rates in Group A and Group B were 56% and 27% respectively, and the rate of the former was significantly higher than that of the latter (p less than 0.05). The 4-year survival rates in Group A and Group B were 83% and 53% respectively. The rate of Group A was also significantly higher than that of Group B (p less than 0.01). We concluded that preoperative Sandwich therapy was very significant to obtain successful long-term disease-free survival and survival in regard to relatively early stage HCC.     

Improved intracranial lesion characterization by tissue segmentation based on a 3D feature map

Our aim was to develop an accurate multispectral tissue segmentation method based on 3D feature maps. We utilized proton density (PD), T₂-weighted fast spin-echo (FSE), and T₁-weighted spin-echo images as inputs for segmentation. Phantom constructs, cadaver brains, an animal brain tumor model and both normal human brains and those from patients with either multiple sclerosis (MS) or primary brain tumors were analyzed with this technique. Initially, misregistration, RF inhomogeneity and image noise problems were addressed. Next, a qualified observer identified samples representing the tissues of interest. Finally, k-nearest neighbor algorithm (k-NN) was utilized to create a stack of color-coded segmented images. The inclusion of T₁ based images, as a third input, produced significant improvement in the delineation of tissues. In MS, our 3D technique was found to be far superior to that based on any combination of 2D feature maps (P < 0.001). We identified at least two distinctly different classes of lesions within the same MS plaque, representing different stages of the disease process. Further, we obtained the regional distribution of MS lesion burden and followed its changes over time. Neuropsychological aberrations were the clinical counterpart of the structural changes detected in segmentation. We could also delineate the margins of benign brain tumors. In malignant tumors, up to four abnormal tissues were identified: 1) a solid tumor core, 2) a cystic component, 3) edema in the white matter, and 4) areas of necrosis and hemorrhage. Subsequent neurosurgical exploration confirmed the distribution of tissues as predicted by this analysis.     

Increase in venous outflow from the corpora cavernosa during mild erection in dogs.

The venous outlet of the corpus cavernosum is generally believed to be obstructed during erection. Some researchers, however, have demonstrated an increased venous outflow during erection. To elucidate this discrepancy, we carried out a pressure-flow study using a perfusion model of the penile deep artery in dogs. Various states of the corpus cavernosum, which were different in cavernous pressure, were induced by a delicate control of electrostimulation to the cavernous nerve. Inflow rate into the corpus cavernosum, inflow resistance and outflow resistance were simultaneously evaluated. The inflow rate in mild erection was higher than in the flaccid state, and the outflow rate was estimated to be also higher than in the flaccid state. A probable reason for the increased outflow rate was that the arterial resistance decreased remarkably, while the venous resistance only slightly increased. In full erection, both the inflow and outflow rates were lower than in the flaccid state because of a great venous resistance. Histological observation of the canine penis indicated that compression of draining veins passing through the tunica albuginea was weak in mild erection, while intense in full erection. It was proposed that in mild erection, the effect of venous occlusion was slight though that of arterial dilation was noticeable, resulting in an increase in the venous outflow.     

Ultrasonic duplex system to facilitate assessment of portal blood flow velocity

The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.     

Modified Two-Layer Preservation Method (M-Kyoto/PFC) Improves Islet Yields in Islet Isolation

Islet allotransplantation can achieve insulin independence in patients with type I diabetes. Recent reports show that the two-layer method (TLM), which employs oxygenated perfluorochemical (PFC) and UW solution, is superior to simple cold storage in UW for pancreas preservation in islet transplantation. However, UW solution has several disadvantages, including the inhibition of Liberase activity. In this study, we investigated the features of a new solution, designated M-Kyoto solution. M-Kyoto solution contains trehalose and ulinastatin as distinct components. Trehalose has a cytoprotective effect against stress, and ulinastatin inhibits trypsin. In porcine islet isolation, islet yield was significantly higher in the M-Kyoto/PFC group compared with the UW/PFC group. There was no significant difference in ATP content in the pancreas between the two groups, suggesting that different islet yields are not due to their differences as energy sources. Compared with UW solution, M-Kyoto solution significantly inhibited trypsin activity in the digestion step; moreover, M-Kyoto solution inhibited collagenase digestion less than UW solution. In conclusion, the advantages of M-Kyoto solution are trypsin inhibition and less collagenase inhibition. Based on these data, we now use M-Kyoto solution for clinical islet transplantation from nonheart-beating donor pancreata.     

Polymorphism of the mast cell chymase gene (CMA1) promoter region: lack of association with asthma but association with serum total immunoglobulin E levels in adult atopic dermatitis

BACKGROUND: Mast cell chymase has the potential to be an important mediator of inflammation and remodelling in the asthmatic lung. Previous studies have examined association between promoter polymorphism of the chymase gene (CMA1) and allergic phenotypes but the significance of this polymorphism is unclear. We have examined association of a CMA1 variant in relation to asthma in a large UK Caucasian family cohort. METHODS: A polymorphism of the CMA1 gene promoter (-1903G/A) was genotyped in 341 asthmatic families and in 184 non-asthmatic adults recruited from the UK PCR-RFLP based genotyping. Association with asthma diagnosis, atopy, specific and total IgE, and atopy and asthma severity was examined. RESULTS: Case-control studies did not reveal a significant difference in allele frequency between asthmatics and controls. A significant association was found between CMA1 genotypes and total IgE levels in subjects with self-reported eczema that remained significant after correction for multiple testing (median total serum IgE GG 297 kU/L, GA 144 kU/L, AA 48.4 kU/L, Pc=0.0032). CONCLUSION: These data suggest that CMA1 promoter polymorphism does not contribute to asthma susceptibility or severity but may be involved in regulating IgE levels in patients with eczema.     

An in vitro evaluation of simplified quantitative diagnostic aids for detection of Candida albicans.

Sensitivities and abilities of quantitative detection for Candida albicans of five simplified diagnostic aids for candidosis or denture stomatitis--Microstix-Candida, Stomastat medium, Mizuno- Takada medium, CA-TG medium, and "milk test"--were examined in vitro, and the characteristics or the indications for clinical use of these summarized.     

Activity of synthetic enzymes of tetrahydrobiopterin in the human placenta

Tetrahydrobiopterin (BH4) is an essential co-factor for nitric oxide (NO) synthase (NOS) and regulates the production of NO, or endothelium-derived relaxation factor. Although NOS is highly expressed in the placenta and NO plays a critical role in the regulation of feto-placental circulation, the mechanism maintaining the level of BH4 is not known. To investigate the de novo synthesis of BH4 in the human placenta, the activity of guanosine triphosphate cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR) in the chorionic tissue during the first, second and third trimester of pregnancy was analyzed. GTPCH activity was the lowest of the three enzymes and became negligible after the second trimester. There was no significant change in PTPS activity throughout pregnancy. Although SR activity decreased significantly after the second trimester, the levels remained abundant throughout pregnancy. These results showed that GTPCH is a rate-limiting enzyme and the total activity of the de novo synthesis of BH4 is negligible in the mature placenta after the second trimester when fetal growth is accelerated. The present study suggests that the level of BH4 in the placenta depends principally on the system other than de novo synthesis. The salvage pathway is considered the most potent system, which is formed by the transfer of the substrates from the fetus and their enzymatic conversion to BH4 in the placenta.